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Using Contractor Bid Amounts to Estimate the Difference between Night-Time and Day-Time Production Rates for Highway and...

Permanent Link: http://ufdc.ufl.edu/UFE0024071/00001

Material Information

Title: Using Contractor Bid Amounts to Estimate the Difference between Night-Time and Day-Time Production Rates for Highway and Bridge Construction
Physical Description: 1 online resource (75 p.)
Language: english
Creator: Thurn, Steven
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: asphalt, cost, illumination, night, pile, signage
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Many studies have debated the use of night-time construction work on road construction is the best possible option. Many studies have examined the overall safety of the construction site. Illumination standards, signage requirements, and crash rate data have been studied to determine increased crash rates during night-time hours, as well as the reasons for these crashes. Many such studies focus solely on safety impacts. Few studies have addressed the cost impacts of night-time construction on a project. Our study used a slightly different approach. We focused more on the different cost impacts of night-time construction on certain types of work throughout the state of Florida: pile driving and asphalt paving. Many studies that have been performed in the past have focused mainly on the safety impacts that night-time construction creates on the environment. These studies make strong cases that night-time construction significantly increases the amounts of accidents throughout a work zone area. Since relatively convincing evidence has shown that night-time construction is a rather risky operation, this study will focus on justifying whether night-time construction profitability can outweigh the danger it imposes on the work zone. Our study provides the state of Florida's Department of Transportation (FDOT), with a meaningful guideline as when to perform night construction projects, if at all.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Steven Thurn.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2008.
Local: Adviser: Minchin, Robert E.
Local: Co-adviser: Obonyo, Esther.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0024071:00001

Permanent Link: http://ufdc.ufl.edu/UFE0024071/00001

Material Information

Title: Using Contractor Bid Amounts to Estimate the Difference between Night-Time and Day-Time Production Rates for Highway and Bridge Construction
Physical Description: 1 online resource (75 p.)
Language: english
Creator: Thurn, Steven
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: asphalt, cost, illumination, night, pile, signage
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Many studies have debated the use of night-time construction work on road construction is the best possible option. Many studies have examined the overall safety of the construction site. Illumination standards, signage requirements, and crash rate data have been studied to determine increased crash rates during night-time hours, as well as the reasons for these crashes. Many such studies focus solely on safety impacts. Few studies have addressed the cost impacts of night-time construction on a project. Our study used a slightly different approach. We focused more on the different cost impacts of night-time construction on certain types of work throughout the state of Florida: pile driving and asphalt paving. Many studies that have been performed in the past have focused mainly on the safety impacts that night-time construction creates on the environment. These studies make strong cases that night-time construction significantly increases the amounts of accidents throughout a work zone area. Since relatively convincing evidence has shown that night-time construction is a rather risky operation, this study will focus on justifying whether night-time construction profitability can outweigh the danger it imposes on the work zone. Our study provides the state of Florida's Department of Transportation (FDOT), with a meaningful guideline as when to perform night construction projects, if at all.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Steven Thurn.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2008.
Local: Adviser: Minchin, Robert E.
Local: Co-adviser: Obonyo, Esther.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0024071:00001


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1 USING CONTRACTOR BID AMOUNTS TO ESTIMATE THE DIFFERENCE BETWEEN NIGHT-TIME AND DAY-TIME PRODUCTI ON RATES FOR HIGH WAY AND BRIDGE CONSTRUCTION By STEVEN BRENT THURN A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2008

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2 2008 Steven Brent Thurn

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3 To my mother and father for always s upporting me in my academic endeavors.

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4 ACKNOWLEDGMENTS Many different people aided m y research. Firs t I thank my parents for supporting me and allowing me to continue with education. Sec ond I thank my committee members (Dr. Edward Minchin, Dr. Esther Obonyo, and Dr. Ralph Ellis). Th ey have been very helpful in assisting me with my research and also helping me form a defined interesting subject. Dr. Minchin has especially been helpful introduc ing me to the topic of nighttime construction, and without him this research project would not have been possible. I would las tly like to thank the state of Florida Department of Transporta tion. All eight districts have been incredibly helpful with my study and have responded to every re quest I have asked of them. I would especially like to thank Debbie Shaw, Pete Nissen, and Angela Woody for guiding me through the inner workings of the Department of Transportation, and gaining me access to their computer system. I am deeply grateful for their efforts.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ............................................................................................................... 4 LIST OF TABLES ...........................................................................................................................7 LIST OF FIGURES .........................................................................................................................8 LIST OF FIGURES .........................................................................................................................8 ABSTRACT ...................................................................................................................... ...............9 CHAP TER 1 INTRODUCTION .................................................................................................................. 11 2 LITERATURE REVIEW .......................................................................................................14 Safety Impact of Night-Time Construction ............................................................................ 14 Introduction .................................................................................................................. ...14 Assessing the Safety Impact of Night Work in Texas ..................................................... 15 Department of Transporta tion State S pecification .................................................................17 Methodology ................................................................................................................... .17 Trend Analysis .................................................................................................................18 Plan and Prevention ................................................................................................................21 Luminance Detection ..............................................................................................................24 Automated DSS Systems ........................................................................................................26 Signage ....................................................................................................................... ............27 3 METHODOLOGY ................................................................................................................. 41 4 RESULTS AND ANALYSIS................................................................................................. 45 Introduction .................................................................................................................. ...........45 FC-6 Friction Course ..............................................................................................................45 Introduction .................................................................................................................. ...45 Percentage Breakdown of State Projects .........................................................................46 Comparison of Differing Construction Methods .............................................................46 Cost Savings ....................................................................................................................47 Superpave Traffic C Structural Course ...................................................................................48 Introduction .................................................................................................................. ...48 Percentage Breakdown of State Projects .........................................................................48 Comparison of Differing Construction Methods .............................................................49 Cost Savings ....................................................................................................................49 Superpave Traffic D Structural Course ..................................................................................50

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6 Introduction .................................................................................................................. ...50 Percentage Breakdown of State Projects .........................................................................50 Comparison of Differing Construction Methods .............................................................51 Cost Savings ....................................................................................................................52 Prestressed Concrete Pilings .................................................................................................. .52 Introduction .................................................................................................................. ...52 Percentage Breakdown of State Projects .........................................................................53 Comparison of Differing Construction Methods .............................................................53 Eighteen inch prestressed concrete piling ................................................................ 53 Twenty four inch prestr essed concrete piling........................................................... 54 Cost Saving eighteen inch Prestressed Piles ...................................................................54 Cost Saving twenty four inch Prestressed Piles .............................................................. 55 Economies of Scale ............................................................................................................ .....56 5 CONCLUSION .................................................................................................................... ...65 Introduction .................................................................................................................. ...........65 Friction Course FC-6 ..............................................................................................................66 Superpave Traffic C Structural Course ...................................................................................67 Superpave Traffic D Structural Course ..................................................................................67 Pile Driving .................................................................................................................. ...........68 Recap ......................................................................................................................... .............69 6 RECOMMENDATIONS ........................................................................................................ 70 Introduction .................................................................................................................. ...........70 Day vs. Night Productivity .....................................................................................................70 State of Florida Cost Analysis ................................................................................................ 72 Crash Test Data ............................................................................................................... ........72 REFERENCES LIST .....................................................................................................................74 BIOGRAPHICAL SKETCH .........................................................................................................75

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7 LIST OF TABLES Table page 2-1 Assessing the safety impact of active night work zones in Texas ..................................... 30 2-2 Individual state nighttim e specification list ...................................................................... 31 2-3 State specification list .................................................................................................. ......38 2-4 Different categories of lamps used on a night-tim e construction project .......................... 39 2-5 Frequency of late braking at Woodland Hills sign (#18) ................................................... 39 2-6 Frequency of late braking at Woodland Hills sign (#18) by age ....................................... 39 2-7 Frequency of late braking at Woodland Hills sign (#18) by visibility .............................. 39 4-1 Friction Course FC-6 savi ngs during the day and night .................................................... 58 4-2 Superpave Traffic C savings during the night ................................................................... 58 4-3 Superpave Traffic D savings during the night ................................................................... 58 4-4 Eighteen inch prestressed piles savings during the night................................................... 58 4-5 Twenty four inch prestresse d piles savings during the night ............................................. 58 4-6 Economies of scale ........................................................................................................ ....58

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8 LIST OF FIGURES Figure page 2-1 El Hyari and El Rayes automated DSS system. ............................................................... 40 4-1 Percentage of Asphalt Friction Cour se FC-6 paving projects (2004-2007) ......................59 4-2 Asphalt Friction Course FC-6 price per ton ....................................................................... 60 4-3 Asphalt Friction Course FC-6 price per cubic yard ........................................................... 60 4-4 Percentage of Superpave Traffi c C paving projects (2006-2007) .....................................60 4-5 Superpave Traffic C price per ton ......................................................................................61 4-6 Percentage of Superpave Traffic D Stru ctural C ourse paving projects (2004-2007) ........61 4-7 Superpave Traffic D Structural Course price per ton ........................................................ 61 4-8 Superpave Traffic D Structural Course price per m etric ton ............................................. 62 4-9 Percentage of concrete piling projects (2004-2007) .......................................................... 62 4-10 Eighteen inch prestressed p ile prices per linear f oot ......................................................... 62 4-11 Eighteen inch prestressed pile prices each ......................................................................... 63 4-12 Twenty four inch prestresse d pile prices per linear foot .................................................... 63 4-13 Twenty four inch pres tressed pile prices each ...................................................................64

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9 Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science in Building Construction USING CONTRACTOR BID AMOUNTS TO ESTIMATE THE DIFFERENCE BETWEEN NIGHT-TIME AND DAY-TIME PRODUCTI ON RATES FOR HIGH WAY AND BRIDGE CONSTRUCTION By Steven Brent Thurn December 2008 Chair: Edward Minchin Cochair: Esther Obonyo Major: Building Construction Many studies have debated the use of night-tim e construction work on road construction is the best possible option. Many studies have examined the overall safety of the construction site. Illumination standards, signage requirements, and cr ash rate data have been studied to determine increased crash rates during night-time hours, as well as the reasons for th ese crashes. Many such studies focus solely on safety impacts. Few studies have addressed the cost impacts of night-time construction on a project. Our study used a slightly different approac h. We focused more on the different cost impacts of night-time construction on certain type s of work throughout the state of Florida: pile driving and asphalt paving. Many studies that have been performed in th e past have focused mainly on the safety impacts that night-time construc tion creates on the environment. These studies make strong cases that night-time construction significantly incr eases the amounts of accidents throughout a work zone area. Since relatively convincing evidence has shown that night-time construction is a rather risky operation, this study will focus on justifying whether night-time construction profitability can outweigh the da nger it imposes on the work zone Our study provides the state

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10 of Floridas Department of Tr ansportation (FDOT), with a mean ingful guideline as when to perform night construction projects, if at all.

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11 CHAPTER 1 INTRODUCTION For the m ost part, night-time construction projec ts are used on heavier traffic flow areas. These areas may include interstate or state roads that are usually located in metropolitan areas. For this reason not all of the states Department of Transportation's (DOTs) practice night-time construction, because the need to work at night is simply not there. States such as Florida, California, and Texas highly practice night-time construction. They continue to evolve and strive to better these processes to create a safer and more efficient work environment, while creating a quality product. It may be surprising to some, but the usage of night-time construction is seen as a highly controversial subject. But what people and civilians do not realize is the fact that there are many different factors that go into plac e when determining if a night-tim e project is feasible. Questions such as; is the road a high volume area, wher e traffic will significantly be impacted by performing work during the day? Which times of the day have the lowest numbers of drivers on this road? What is the size of the construction s ite and what are the needs as far as illumination requirements are needed to complete the work? What lengths of road can we expect to close at any given time? And are the proper signage and ba rriers in place during th e night-time? All of these items are among the questions that need to be answered befo re determining to enter into a night work contract. The presence of night-time construction work can be seen as early as the 1960s. (Ullman 2007) There were many reasons that ultimately led to the decision behind performing work during the night-time. First, by performing the wo rk during the night, construction workers have the opportunity to work during a time period that is much cool er than the day-time. This becomes especially important when construction wo rkers are performing work in southern states

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12 such as Florida and Texas. Secondly, by performi ng work at night, the construction workers are able to more freely accept material deliveries, as well as perform work that tends to take more space than other processes. The traffic congestion is noticeably lower during the night-time hours and this greatly benefits the c onstruction crews. Lastly, the pr esence of night-time construction greatly alleviates the stress that the presence of day-time construction has on the traveling public. If the work were to be performed during the day-time, it would occur duri ng the highest times in commuter traffic. By performing the constr uction during the night-time, it allows the construction workers to close dow n portions of the road during a relatively low traffic hour. This benefits both motorists and the contractor. Although there are many benefits that can be seen by performing road work during the night-time, there are many factors that occur during night-time work that can be seen as detrimental. Ullman performed a study in 2007 that concluded by perf orming work during the night-time the quality of the work actually suffe rs. Studies have confirmed that workers who tend to work the long hour shifts, that night work usually demands, have been negatively affected by reductions in their individual sleep times, the amount of undue stress that is placed on the body, and it also greatly affects the work ers appetites. Other perceptions are that by working during the night-time will greatly affect the workers react ion time, alertness, and motor skills. It becomes especially important for worke rs to be all of the a bove (alert, have a short reaction time, and have full usage of their motor skills) in order to perform the work both safely and in a quality manner. In actuality these results seen above have not been proven, but it still becomes important to take these factors into acco unt when dealing with night-time construction. The purpose of this study is to take a l ook into some commonly performed construction processes that take place on interstate construc tion jobs. These jobs will include asphalt paving

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13 and pile driving. These items will be studied on projects taking place throughout the state of Florida from the years of 2004-2007. These projects will be separated into projects that occur during the day-time, during the night-time, and pr ojects that occur durin g the day and during the night. Once these projects have been analyzed they will be averaged and then compared to other similar projects performed during different times of the day as well as the state averages. By comparing the average data to state averages it wi ll allow the researcher th e ability to determine if there is a significant difference between the valu es that were attained by construction projects performed during the night-time and the constr uction projects performe d during the day-time. The general idea is to help prove that there is in fact a noted di fference in the costs associated with performing construction during the night compared to the da y. Since it is not feasible to manually put researchers on individual projects to determine their production levels, the study will assume that the differences in costs between projects will inevitably reflect the differences in overall productivity be tween the projects.

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14 CHAPTER 2 LITERATURE REVIEW Safety Impact of Night-Time Construction Introduction One of the more heavily studied factors involving night-time constr uction is the impact that the construction has on the sa fety of the project. Proponents of night-time construction argue that there are many items present in night-time construction work th at results in it being safer than that of work during the day. For one, ni ght-time construction site s are performed during times when the road has the least amount of driver s on it. It does not take an expert to realize, that with the decreasing number of drivers on th e road, there will be le ss possible cars that will be able to get into a wreck near the job site. Secondly, work can be performed during the nighttime when temperatures are lower, this would aid in the overall stamina and alertness of the construction worker on the jobsite. Lastly, by performing certain work processes during the night-time, it gives workers the opportunity of working in much more spacious environments. With the added room that the night offers, worker s are able to spread out and perform their work in their own spaces without fear of being inju red by other trades (Ullman, Finley, and Ullman 2007). Even though many believe that by working dur ing the night-time is inherently safer, many experts disagree. Many believe that because of the lack of lighting that is present during the night-time, a construction site actually become s more dangerous, despite the lack of traffic. In addition experts believes that by narrowing the roadway at a period where illumination is poor, and on average drivers are at their least attentiveness, the work site is in far more dangerous than it would be while working during the day-time hours.

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15 Assessing the Safety Impact of Night Work in Texas There have been many studies performed on th e subject of safety through out night time projects, including one in the 1980s that took place in California. Researchers studied a number of work sites throughout the state of California and determined that for areas that included active night work zones, accidents increased over the average number of interstate wrecks by 87%. It was furthermore concluded that wrecks increased by 75% when one of the lanes were closed in comparison to no lane that was closed. A similar study conducted in Virginia confirmed the data that was found on the California stud y, and it further gave credibility to the dangers of night-time construction. Despite the findings that were uncovered in bo th the California and Virginia studies there still can be strong arguments for the usage of ni ght-time construction. One could argue that there are actually lower numbers of wrecks that occur during the night than pr ojects that take place during the day. This can be rationalized due to the fact that the lowest amount of drivers travels during the night-time. Even though an increasing ly large amount of th ese drivers get into accidents, there still might be fewer accidents that would occur during the night-time in comparison to the large sample size of drivers that could potentially get in to accidents during the day-time. (Ullman, Finley, and Ullman 2007) Another important study regarding night-tim e safety took place in Texas between the dates of June 2002 May 2003. This study broke dow n a construction site into four different work processes and then determined which processes were the most dangerous and which were the least dangerous. The first work process was demolition and structural repair. This work process was considered to be relatively dangerous because much of the works performed were on overpasses that were above oncoming traffic. Becau se of the danger associated with this work type, it was determined that this work should be completed during the night-time. The second

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16 work process that was considered was concrete pours. It is common pr actice to pour concrete during the night-time hours due to the high temperatures that are encountered during the day. The third work process that was studied was paving. Paving entails milling, sealing, and overcoat and much like the other processes mentioned it is more preferred to be performed during the night-time. The last process that was studied wa s striping. Striping is an extremely slow process. Because of this it only becomes rational that st riping be performed during the night in order to reduce the effect that it would have on traffic. Once the researchers had structured their re search project they decided to put it into action and study active work zone s throughout the state of Texas. Their studies found that throughout this time period there were 280 active pr ojects. Of these active projects, 39 of them included night work (70% of the 39 projects in cluded night work and day work, and 30% of the 39 projects solely performed night work). The researchers were able to find accident data describing the number of wrecks in or around the work zone area but they were not able to determine if these accidents necessarily happened while the construction site was active. If the researchers were to assume that the work zone s were active during each of the accidents than it would be concluded that night-tim e work greatly increases accident rates on the interstate (Table 2-1). By further analyzing their data the researchers determined a number of things. First they determined that inactive work zones only experi ence a slightly higher ac cident rate than do non work zone areas. In work zones that were activ e during the day-time, the research found that the average crash rate increased by 36.5%. After determining the effects of active and non active work zones on crash rate data for day-time projects the researcher s decided to perform the same study for projects during the

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17 night-time. This research found th at for non active work zones rece ived a 45% increase in annual accidents. For projects that had currently active night work zones, the accident rate ballooned to a 102% increase. After analyzing the data it becomes pretty clear that night work areas have a pretty drastic effect on the safety of the overall project. Lastly once the data was thoroughly studied it was proven that the most dangerous it em of work during a night work construction project is resurfacing. While resu rfacing projects were underway th roughout the state of Texas, accidents spiked by 55.4% (Ullman, Finley, and Ullman 2007) After looking at the previous studies a ve ry strong case can be made that night-time construction is inherently risky. Because of th is, it is important to properly illuminate and barricade the projects to ensure the maximum amount of safety is given to the drivers on the road as well as the workers inside the work zone. The lo ss of one life is too much. Data suggests that 100 workers die annually in roadway constructi on related accidents, while another 20,000 are injured. Vehicles and equipment that are currently working inside the active work zone or are currently are passing by the work zone account for ove r half of the total fatalities. Measures have been taken in the form of increased usage of fla gger stations as well as the improved quality that states Department of Transporta tion are requiring as far as ligh ting is concerned. It has begun to make a difference in that less th an half of the overall construc tion deaths that have included being struck by vehicles, have happened from cars coming from the road into the work site. Department of Transportation State Specification Methodology To reiterate, night-time c onstruction has only been a legitimate option since the 1960s. Since that time some states have warmed to the idea while other states have not. For the most part, states that have a high volume of metropo litan areas or interstate highways are more comfortable with night-time work than are states th at reside in more rura l areas. Nevertheless my

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18 first study on the subject of night-time constr uction was to come in contact with each construction office of each individual states depa rtment of transportation (including Washington D.C. and Puerto Rico). Once I came in contact with someone who was familiar with the inner workings of night-time work procedures I began to ask them a series of five questions. Does your states department of transporta tion do anything special regarding night-time construction? If so then what do they do? Does your state have a specifi cation book that solely deals wi th night-time construction? Or does your state have an item in your specifi cation book that solely deals with night-time construction? Does your state have any specifications for illumination? Other than illumination what else can be found in the specifica tion book regarding nighttime work? Can the specification book be found online? Once these questions were answered the data was put into a table a nd analyzed to better determine the overall feeling that the nation has towards night-time work construction. Trend Analysis Once the data was analyzed it becam e apparent that there were a number of trends that could be seen between states. The first trend that was noticed was that a ll states perform nighttime construction in some manner. To clarify th ere are states with hi gher populations such as California, New York, Florida et c that consistently have ni ght-time construction projects, while states with lower populations such as No rth Dakota, South Dakota, Montana etc rarely perform night-time construction beca use there is simply no need to. The second trend that can be noticed from the st udy is that nearly half of the states, 25 of the 52, interviewed had some sort of specifica tion book dealing with night-time construction. This was the most important item of the study. It is important for states that perform construction processes during the night to ha ve a well defined specification book to draw from. The more well defined the specification book becomes, the less conf usion that will be present on the jobsite, and

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19 this should lead to a potentia l decrease in accidents while on th e job. These items were analyzed to determine to which extent states ha ve night-time specifications (Table 2-2) The third trend that was noticed throughout the study was the overall importance that was placed on illumination standards. Illumination st andards were the overall dominating feature in contractors specification books as well as contractors plans. Of the 25 states that had night-time specs, 24 of them have individual specs dealing with the specific illumination standards that should be present on the jobsite. (with Kansas being the lone exception of states that have specifications but not illumination specifications) States have reali zed the overall importance that lighting has on the productivity, qua lity, and safety of the constr uction site. After conducting the interviews it became apparent that even for states that might not have had individual specifications dealing with night-time work, they still had specific plans in place mandating the usage of ample lighting by contractors. One interesting state that should be taken not e of is Alaska. Alaska particularly needs illumination specifications. If not already known, Al aska witnesses the night for long expanses of the year, so it is most important for them to have illumination specifications more than any other state because they are almost forced to work during the night. Alaska mandates that there be specific balloon lighting througho ut the project as well as al so mandating different forms of lighting depending on the machinery and work th at is to take place during the project. It has already been stated that 96% (24/ 25) of the states that had specification books dealing with night-time construc tion had a spec dealing with illu mination. This is far and away the most controlling item of interest of each st ates spec book. Only 64% (16/25) of these states had anything else in their spec book involving any other item of work. One of these items includes the usage of retro reflect ive gear and flagger stations. St ates adhere strictly to the

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20 guideline put in place by the MUTCD (Manual on Uniform Traffic Control Devices). The MUTCD requires that flagging stat ions and workers wear the neces sary ANSI rated two or three level vests. This allows flaggers and workers for that matter to be clearly seen by oncoming traffic. Once these workers are seen by oncomi ng traffic, there is a lesser chance that will be struck by or injured by the oncoming cars. The next item that was commonly used by st ates departments of transportation was the usage of lane closure standards. There are six states that have something written in their specifications solely dealing with lane closure standards. These states in clude Florida, Illinois, Massachusetts, Nebraska, Oregon, and Virginia. These states have specif ic plans in place in order provide lane closures in times where th e traffic levels are cu rrently low and can be managed. The third most prevalent item in states spec books are the usag e of signage. Signage becomes important to help prepare the driver to when there will be construction coming. This allows drivers to explore alternate routes to their destination, which is a benefit to both the driver and the contractor. If they are not able to find a se condary route, it allows the driver to slow their car down before driving through a dangerous zone, to prevent accidents. These states that have specifications dealing with si gnage include Connecticut, Flor ida, Nebraska, and New York. Guardrails and state troopers were the last two items that were mentioned through out the interview. Guardrails being used obviously for pr otection for workers inside the work zone area. State troopers were to be used to help enfor ce the authority of safe driving and behavior throughout the work zone area. In al this study proved that there is s till much to be done in the way of planned development of night-time construction. Less th an half of the states interviewed had

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21 specifications dealing with night-time constructio n and that is far too low. Hopefully in time better plans will be formulated a nd adopted by each state, in order to ensure a safer working environment. To conclude the study, a table was organized to fully show which states have their nighttime specifications on the internet (Table 2-3). Plan and Prevention Since it has been shown in one of the more recent studies that it is more than 85% likely to get into an accident when night work constr uction is taking place, many experts decided to find a way to manage the dangers on night-tim e construction projects and develop a traffic management system (Anderson and Ullman 2000) This study hoped to develop a system which can notify drivers where alternate routes may be. This would reduce the amount of traffic on the road at the time of construction, which would in evitably lead to fewer wrecks. Much to their amusement, studies have shown that motorist will typically take alternat e routes when they are provided to them instead of having to drive through an active work zone. To develop this traffic management program th e researchers had to keep a number of items in mind. They had to be aware of the economic im pacts the construction w ould create, the impact it would have on safety, the overall publics point of view on the construction, as well as keep in mind the overall traffic strategies of the project. The first matter of business that should be considered when determining a traffic management is the economic impact it will ha ve. While implementing one of these plans, contractors are able to instal l a number of surveillance equi pments. The items may include closed circuit televisions, inducti ve loop, radar, microwave, and other vehicle detectors. This would allow the team to study and determine which are the best times to perform the projects, as well as closely monitor the items of severe cons equence. The traffic management system also

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22 has the ability to notify the oncoming public by improving traffic signals as well as Traveler Information Systems that include highway adviso ry signs and stations, kiosks, radio stations, etc This is a decision that the department of transportation must make while they are deciding on the course of action they will take. On larger sized projects it might be a good idea to spend the money and make sure that the project is well run because the impact of an accident could be much greater. (Anderson and Ullman 2000) In many states the decision has been to cu t cost and to have many different tradesmen work in the same active work zone. This will mi nimize the amount of time th at there will be lane closures, but it can also be assumed that it increases the risk of accident within the site due to the amount of simultaneous work taking place. It also reduces the cost to the motorist who is impacted by traffic delays by the cost of $10-$13 per hour. (Anderson and Ullman 2000) The next thing that must be taken into account while developing a traffic management plan is the safety impact it will have. Throughout the United States, each states department of transportation is beginning to develop its own specification book dealing with night-time construction. The most important of these specif ication items would be illumination standards. Currently the MUTCD requires that retro reflective vests be worn by workers and that there must be flagging stations around dangerous work ite ms. Also, contractors and the department of transportation are working together to determine what the specif ications for lighting should be for individual items of work, wh ile at the same time determining what the allowable glare rating is to be for oncoming traffic. (Glare is importa nt because it can impair the sight of the oncoming traffic) The third item that must be taken into acc ount would be the perception of the public. A construction process should be performed in different ways depending on the geographical

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23 location. For instance, if a constr uction process is currently locat ed in or near a residential neighborhood maybe the usage of night-time construction would not be the best choice. Families enjoy their peace and privacy during the night-tim e hours. The same can be said for performing construction work in front of businesses. Business es would prefer for the work to be done during the night-time, so as not to deter customers from coming during the day. It is very important to take the publics perception to he art. (Anderson and Ullman 2000) The last thing that should be taken into acc ount is the different tra ffic handling strategies. There are many different ways that a contract or can optimize the production on a project while minimizing the amount of traffic. For instance portable concrete barri ers and paddle screens allow contractors to become mu ch more mobile when it comes to roadway construction. They can manually place the barriers only at times when work is to be performed. Secondly they could close down entrance ramps that enter into the work zone itself. This will limit the amount of cars that will be driving through the work zone and th erefore relieve the amount of stress that traffic imposes onto the construction site. The usage of roadway shoulders as lanes can also help alleviate the stress of traffic by a dding an additional lane for through traffic. If this is not a viable option the usage of reversible lane can also be seen as an option. This includes closing down a lane of say the North side of the interstate and allowing South travelers to use that lane while one of their lanes is closed down by construction. Las tly the usage of service patrol to immediately remove and clean up accidents if they do happen would greatly reduce the impact of traffic. While performing an interstate project it is extremely important to plan the construction process before hand. By planning th e project before hand it allows the contractor the foresight to determine which items are profitable and whic h items are losing money. It also gives the contractor the opportunity of seque ncing items, equipment, and labor forces at optimal times to

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24 reduce the amount of unproductive time. The us age of value engineering would be a great addition to the construction planning process. Once you have considered which kind of impact each of these factors will have on the project a number of items need to be determined in order to deve lop the traffic management plan. These items can be seen below. Type of work Encroachment required (storage buffers, and loading areas) Project work limits Tentative schedule Time periods that the area will be occupied Location of the nearest utilities Work vehicle entrances and exits. Once all of these items have been considered the traffic management plan is ready to be developed and implemented. (Anderson and Ullman 2000) Luminance Detection While a project is going through the planning stages it first is determined if the project will be performed during the night-time or during th e day. If it has been chosen to be performed at night another set of questions must be answered. These questi ons deal with the usage, amount, and the overall ratings of the li ghts that are necessary to work on the project. A study was performed to citing the four main factors to cons ider when determining which kind of lighting to use on the construction project (Ellis, Amos, and Kumar 2003). The first item that must be considered wh en developing a proper lighting plan is to determine what kind of work is to be performed on the project. If a projects work zone is a larger than normal area and the item of work be ing performed in this work zone area is also riskier than normal that it is preferred that the work be performed in a more well lit area. This will provide the workers who are working in the work zone area a more detailed view of the

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25 work that they are performing. C onversely to this example, if wo rk zones are in small areas and the work items that are being performed are rather menial and less risky, ample amounts of lighting might not be necessary. This will not on ly conserve cost on the project by reducing the amount of lighting towers but it wi ll also reduce the glare to the onc oming traffic, which will in turn reduce the number of work zone crashes. (Ellis, Am os, and Kumar 2003) The second item that must be considered in determining the amount of lighting on a project would be the overall age of drivers traveling through the work zone area. Studies have proven that the older the driver is the less reactive that they are to items in their environment. In areas where the average age of drivers is expected to be hi gh, higher levels of illumination should be increased. (Ellis, Amos, and Kumar 2003) The third item that impacts work zone il lumination standards are the average speeds throughout the work zones. Studies ha ve also proven that the faster that drivers tr avel in their cars the less aware they are of their surroundings. In night-t ime environments drivers tend to drive at higher speeds for a multitude of reasons. One such reason being that there are fewer people on the road, these promoting faster traveli ng speeds. In areas where the speed limits are higher drivers are much less aware and therefore more likely to get into accidents. Proper lighting should be adequately adjusted to the speeds of the roads whic h construction work is being performed. It also might be in the better judg ment of the general contractor to either reduce the speed limit through the work zo ne area and/or employ the servi ces of state troopers to police the speed through the work zone area. The last item to be considered when introdu cing lighting plans, are the overall presences of lighting glare that affect the traveling public. While performing construction work on a roadway project during the night, it becomes very important to have ample lighting. Contractors

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26 walk a very fine lighting while determining th e amount of lighting that is sufficient enough to perform a construction process without causing po tential harm to the oncoming traffic by the likes of glare. It must be determined by the type of work is to be accomplished what is the necessary amount of light needed for a certain item of work. On ce this lighting level has been reached, it is also important that this level no t be surpassed further endangering the oncoming public. With the usage of this four point lighting plan contractors can mix and match different needs in order to determine the safest and most productive lighting plan that they can develop. Table 2-4 shows there are a number of different la mps, which are used on the construction sight. In addition to this are the output levels of each of the lamps, the mounting heights, and the types of work that these lamps are used for on th e construction site. (Ellis, Amos, Kumar 2003) Automated DSS Systems El Rayes and Hyari (2005) developed an automated decision support system (DSS) that would accomplish the four main categories that dealt with night-time c onstruction. Their ideas were to theoretically develop a system that would maximize the amount of light throughout the work zone area, with an evenly distributed b eam, while minimizing the amount of glare the light would create to oncoming traffic. Once these fact ors have been determined the contractor must decide on a DSS system that is the most cost efficient. Taking these four variables into account, El Rayes and Hyari began developing their lighting plan for their construc tion project. Their lighting plans consisted of seven different variables (Figure 2-1). (Rayes and Hyari 2005) Once the contractor has determined the type of work that is being performed, as well as the size of the work zone, he/she can develop a useful lighting plan with the usage of these seven variables.

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27 Signage Another factor that has been studied with the intention of improving construction work zone safety is roadway signage. Studies have sh own that roadway signage plays a great part in the safety of a job site. Treat (1977) said in one of his studies that ove r 40% of accidents occur from difficulties of percepti on, attention, and distraction. By improving the awareness of the drivers traveling through the wo rk zone area, contractors can almost reduce the amount of accidents taking place in the work zone by half Macdonald and Hoffman (1991) went on to further say that limited attention capacity is a la rge factor in sign recognition. Because of this fact it is imperative that the de partment of transportation as well as the contractors make the sign easy to read, as well as visually noticeable ( by coloring it bright neon colors). (Anders 2000) To further elaborate on these studies Anders decided to determine if the different colors of signage and the overall attention span of dr ivers had any effect on the accident rates through work zone areas. To accomplish this study he di d a number of things. First he handed out a questionnaire randomly to a number of drivers asking what are the most visually appealing colored signs that the drivers noticed and rea d. Secondly he studied a number of expanses of road and recorded the number of late braking ma neuvers and turn errors that drivers encountered. These two errors are very co mmon with drivers who are not currently aware of their surroundings. (Anders 2000) Once the data was accumulated and analyzed a number of items were determined. First the majority of late braking ma neuvers and turn errors occurred with older drivers. This is consistent with the findings stated earlier by El lis, Amos, and Kumar, stating that since older people typically have worst eye sight and lower re action times more lightin g should be used if it is expected that many of the drivers traveli ng at night are elders. Because of this it was

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28 concluded that in areas where olde r drivers are expected to be the majority of travelers, there should be more illuminated and fluorescent signage. Anders also determined by the questi onnaire, that non fluorescent yellow and non fluorescent purple were the least appealing colors of signage fo r those driving. Instead both the older and younger groups of driv ers preferred black lettering on both a fl uorescent yellow and fluorescent green signs. These colors were prefer red because the contrast between the fluorescent signs and the black lettering allowed drivers to read the signs easier than the non fluorescent signage would. To no surprise it was determined that st atistically there were more late braking maneuvers and turn errors that occurred during th e night than during the da y. This data has been consistent with the other studies on the subject, further proving that drivers are less aware of their surroundings dur ing the night. Anders continued the study in more detail by comparing three differe nt items. The first item was to determine if there were as any differe nces in driving behavior that occurred by the different colorings of signs (Table 2-5). The se cond item, studied the same expanse of road, but instead looked at the average age of the driver This study would not only prove that older people are less aware of their surroundings but it would also show which color combinations are most noticeable for both younger and older drivers (Table 2-6). The last item compared, was a study that determined to what extent does driving du ring the day and driving during the night have on a drivers awareness (Tab le 2-7). (Anders 2000) This study concluded by showing fluorescent si gnage is much preferred by drivers on the interstate. These drivers are able to notice the signs quicker and are able to read these signs clearer due to the fact that they glow in the da rk. This is not where th e benefit of fluorescent

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29 signs ends however. An additional study that to ok place in North Carolina concentrated on the effect that fluorescent signage ha d on interstate drivers. This study found that fluorescent orange signage actually affected the behavior of dr ivers on the road. During this expanse of road, researchers noticed that in areas with these fluor escent orange signs there occurred fewer traffic conflicts, fewer cars driving in the left hand lane and cars tended to gravitate toward the right lane more often than normal. In addition to all of these things the aver age speeds of the cars traveling on this road were less normal. (Anders 2000) In the end it is proven that the usage of fluorescent signage is beneficial to night-time construction. They are more easily read by the dr ive and they are also far more preferred by the driver as well. The usage of neon signage in the work zone will allow the driver to become fully aware of the situation that lies before them in the work zone, which in turn will hopefully significantly reduce the probability of crashes during construction.

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30 Table 2-1. Assessing the safety impact of active night work zones in Texas Night work category Districts with rare night work Districts with significant night work Daytime work zone crashes 4,903 Total2,987 (61%) Severe 15,806 Total10,530 (67%) Severe Daytime non-work zone crashes 94,652 Total63,724 (67%) Severe 250,811 Total169,756 (68%) Severe Nighttime work zone crashes 1,545 Total984 (64%) Severe 6,8014,214 (62%) Severe Nighttime work zone crashes 38,707 Total23,986 (62%) Severe 100,310 Total63,131 (63%) Severe

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31 Table 2-2. Individual state ni ght-time specification list States Special nighttime work procedures Nighttime work specs Illumination specs Other requirements in specs Comments Alabama None No No None Contractor has to perform the work that will be inspected by the DOT Alaska Yes Yes Yes None Specific lighting needed for work processes and machinery. Use balloon lighting Arizona None No No None Only puts disincentive in contract for contractors who do not open by specific times in morning. Uses police for lane closures. Arkansas None No No None Follows the MUTCD strictly. This includes reflective cones and barriers Nothing else is mandatory for nighttime construction. California Yes Yes Yes (High Visibility Permits, Reflective ANSI 2 Vests) Items on the jobsite such as cones and barriers must be reflective. Lighting must be to OSHA standards. Colorado Yes No No None There will be special work configurations for night work. There are no specifications; it is more of a state policy. Connecticut Yes Yes Yes (Crash Trucks, Signage, and State Trooper Requirements There are specific specifications for night work. This mostly involves lighting and the other items mentioned.

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32 Table 2-2 (Cont) States Special nighttime work procedures Nighttime work specs Illumination specs Other requirements in specs Comments Delaware Yes No No None Do not necessarily have light specs, but when night work is necessary they use a specific manual. This manual deals with lane closures, lighting necessities, and reflective clothing. Florida Yes Yes Yes (Materials, Lane Closures, Guardrails, Signage, etc...) There is maintenance for traffic and standards to be the same for quality. DOT does lane closure analysis searching for best time. Georgia None No No None The state has made provisions to improve the reflectivity of vests and safety gear. Hawaii Yes No No None Specific areas throughout the state must achieve permits in order to perform work of certain noise levels and lighting levels. Idaho None No No None Idaho has no specifications for night work. When night work is done, provisions are put in the contract. Illinois Yes Yes Yes (Traffic Control Standards, Lane Closure Ramps, etc...) There are details on how lane closures will be set as well as other processes on how to determine lane closure ramps. Indiana Yes No No None This DOT follows the MUTCD. Requires that work sites be illuminated for workers. Also they require reflective vests and gear.

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33 Table 2-2 (Cont) States Special nighttime work procedures Nighttime work specs Illumination specs Other requirements in specs Comments Iowa Yes Yes Yes None Currently the only items in the state of Iowa's specification book relate to lighting standards. Kansas Yes Yes No (Materials, Equipment, Reflective Gear) Illumination standards are up to the contractor to determine how much light is needed to perform the work. Kentucky None No No None This state requires that the OSHA minimums must be met. This includes reflective gear, etc... Louisiana Yes Yes Yes (Equipment, Light Meters, Glare Control, Lighting Plan) All of the items that the state of Louisiana concentrates on deal solely with illumination standards. Maine None No No None Lighting requirements will be decided on a per project basis. There are requirements for reflective gear. Maryland Yes Yes Yes None Lane Closure Standards. Additional signage. Lighting is specific to light operations. Massachusetts Yes Yes Yes (Lane Closure Standards and Usage of Drums for Barriers) Police Troopers may be employed by contractor. Lighting on paving operations required. Michigan Yes Yes Yes None The only thing that the state of Michigan does for night-time work is lighting standards and specifications. Minnesota Yes No No None They adhere to the MUTCD, and all of the requirements for lighting are set out on a project by project basis.

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34 Table 2-2 (Cont) States Special nighttime work procedures Nighttime work specs Illumination specs Other requirements in specs Comments Mississippi Yes Yes Yes None Mississippi has a different set of lane closure standards for day and night-time construction Missouri None No No None Lighting on each project is completely up to the contractor. This state also has some lane closure procedures. Montana None No No None Montana follows the MUTCD guidelines very strictly. They also require lighting on a project specific basis, in which the requirements will be in the special provisions of the contract documents. Nebraska Yes Yes Yes (Lighting Signs, Traffic Controls, Reflectivity) This state has one of the most well defined plans regarding night-time construction. Nevada Yes No No None All of the traffic control meets MUTCD standards. Towers are lit. Boards and press releases warn of lane closures. New Hampshire None No No None This state only follows MUTCD guidelines when performing night work. New Jersey None No No None Illumination standards are completely up to the contractor. DOT has no such specifications. New Mexico None No No None This state does not have any specifications regarding night-time work. This is the contractors responsibilities.

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35 Table 2-2 (Cont) States Special nighttime work procedures Nighttime work specs Illumination specs Other requirements in specs Comments New York Yes Yes Yes (Visibility Requirements and Sign Sheet Signage) The state requires different areas for night work, different illumination for work processes, and high visibility apparel. North Carolina Yes Yes Yes (Reflective Flagging) The contractor shall provide the items necessary in order to provide the lighting specs North Dakota Yes Yes Yes (ANSI 3 Full Reflective Gear) Night work is very rare but there still are a number of provisions for night work. Most importantly there is lighting standards Ohio Yes Yes Yes None Not in the specifications, there are lane closure maps that are used by the DOT to aid in the flow of traffic during construction. Oklahoma None No No None There are no minimum illumination requirements. Night work illumination is completely up to the contractor. Oregon Yes Yes Yes (Reflective Flaggers and Lane Closure Standards) This state's DOT performs lane closure standards, illumination requirements, etc... Pennsylvania Yes No Yes (Work Zone Traffic Control, Taper Lengths) This state has traffic control specifications that control specs for illumination in the work zone. Rhode Island Yes No No None Follow MUTCD strictly and will inspect contractors lighting plans. Make sure the usage of flaggers and or police depending road size

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36 Table 2-2 (Cont) States Special nighttime work procedures Nighttime work specs Illumination specs Other requirements in specs Comments South Carolina Yes Yes Yes None The state of South Carolina requires the specific usage of lighting as well as the usage of reflective drums as barriers. South Dakota Yes Yes Yes (Reflective Flagging) They require the usage of lighting on the project only Tennessee Yes Yes Yes None The only necessity is the needs for illumination requirements. Texas Yes No No None Texas requires that lighting requirements be based on a per project basis. Each district might make a specific plan regarding night work but it is not in the spec book. Utah Yes Yes Yes (Flagger Equipment and Clothing, Reflective Drums) Utah requires that the usage of lighting and the usage of reflective gear and drums are necessary. Vermont Yes No No None Vermont adheres to a standard of lighting put forth by the FHWA. They do not require there own lighting specification. Virginia Yes Yes Yes (Lane Closure Standards, Flagging, State Troopers) Specification deal with lighting angles, illumination, lane closure standards, flagging, and state troopers. Washington Yes No No None Lane closures are given traffic control plan that contractors may alter. No real lighting spec but concentrate on usage of flaggers.

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37 Table 2-2 (Cont) States Special nighttime work procedures Nighttime work specs Illumination specs Other requirements in specs Comments West Virginia Yes Yes Yes None They use temporary lighting and a new channelizer cone for easier and quicker set up for contractors. Wisconsin No No No None Wisconsin does not do anything special regarding night-time work or illumination requirements. Changes to night work are project specific. Wyoming No No No None All the state requires is that the site is well lit. Engineer makes decision. Washington D.C. No No No None Follows the standards put forth by the MUTCD but does not have a defined spec book dealing with night-time construction. Puerto Rico Yes Yes Yes None Puerto Rico has currently developed an illumination plan dealing with nighttime construction.

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38 Table 2-3. State specification list States Specification website address Alaska http://www.dot.state.ak.us/stwddes/dcsspecs/asse ts/p df/hwyspecs/specialprovs/specials_101507. pdf California http://www.dot.ca.gov/hq/esc/oe/index.html#standards Co nnecticut http://www.ct.gov/dot/cwp/view.asp?a=1385&q=259494 Flori da http://www.dot.state.f l.us/sp ecificationsoffice/2007BK/102.pdf Illinois http://www.dot.state.il.us /d esenv/hwyspecs.html Iowa http://www.dot.state.ia.us/speci ficatio ns/dev_specs/DS-01081.pdf Kansas http://www.ksdot.org/burConsMain /sp ecprov/2007SSDefault.asp Louisiana http://www.dotd.la.gov /do clist.asp?ID=50 Maryland http://www.sha.state.md.us/businesswithsha/bizStd sSpecs/desManualStdPub/publicationsonline/ ohd/Start.pdf Michigan http://mdotwas1.mdot.state.mi.us/public/specbook/ Mississippi http://www.gomdot.com/Divisions/Highw ay s/Resources.aspx?Div=Construction Nebraska http://www.dor.state.ne.us/r ef-man /specbook-2007.pdf New York https://www.nysdot.gov/portal/page/portal/main/businesscenter/enginee ring/specifications/specs -repository/Specbook2006TableErrata.pdf North Carolina http://www.ncdot.org/doh/preconstruct/ps/speci fications/english/2006.html (Gen Specs and Specials Provisions) North Dakota http://www.dot.nd.gov/dotnet/supplspecs/StandardSpecs.aspx Ohi o http://www.dot.state.oh.us/constructio n/OCA/Specs/2008CMS/2008_ODOT_C&MS.htm Oregon http://www.oregon.gov/ODOT /HWY/SEOPL/d ocs/manuals/specification-manual.pdf Pennsylvania http://www.dot.state.pa.us/Internet/Bureaus/pdDesign.nsf/ConstructionSpecs408and7?readForm South Carolina http://www.scdot.org/doing/StandardSpeci ficatio ns/pdfs/2007_full_specbook.pdf South Dakota http://www.sddot.com/Operations/specifications/index2004.htm Tennessee http://www.tdot.state.tn.us/construction/Supplemental%20Specs%202006/SS700.pdf Utah http://www.udot.utah.gov/main/f?p= 10 0:pg:799439532877892:::1:T,V:1945 Virginia http://www.virginiadot.org/business/resources/WAPM-2005Revised10_05.pdf West Virginia http://www.wvdot.com/engineering/Specifications/2003/Y2KSpecB.pdf

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39 Table 2-4. Different categories of lamps used on a night-time construction project Category 1 541x (5 ft candles) Category 2 1081x (10 ft candles) Category 3 2161x (20 ft candles) Lowest quality light Recommended on or around equipment and the visual tasks of these equipments such as resurfacing Needed for tasks that have higher difficulty and require more light usage. Should be used for low accuracy work Slow moving equipment Crack fillings, critical connections and maintenance of electrical devices, or moving machinery Large sized equipment to be seen Table 2-5. Frequency of late brak ing at Woodland Hills sign (#18) Sign color combination No late reaction observed Late reaction observed Black on fluorescent yellow-green 16 4 Non-fluorescent yellow on nonfluorescent purple 18 3 Black on fluorescent coral 15 5 Fluorescent yellow on fl uorescent purple 16 5 Table 2-6. Frequency of late braki ng at Woodland Hills sign (#18) by age Sign color combination Olde r drivers Younger drivers Black on fluorescent yellow-green 2 2 Non-fluorescent yellow on nonfluorescent purple 3 0 Black on fluorescent coral 4 1 Fluorescent yellow on fl uorescent purple 5 0 Table 2-7. Frequency of late braking at Woodland Hills sign (#18) by visibility Sign color combination Daytime Nighttime Black on fluorescent yellow-green 0 4 Non-fluorescent yellow on nonfluorescent purple 1 2 Black on fluorescent coral 2 3 Fluorescent yellow on fl uorescent purple 1 4

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40 Lighting equipment selection : determine if need ground mounted towers, trailer mounted towers, and equipment mounted luminaries. Type of lamps : metal halide lamps, high pressure sodium vapor lamps, halogen lamps, and low pressure sodium vapor lamps. Lamp lumen output : Represents energy of lamp, influe nce visual comfort and luminance Mounting Height : Portable lighting towers are made with adjustable heights up to 25m. Lighting tower positions : Influences average illuminance and lighting through the site. Luminaries lighting angles : angle of beam of light and nadi r, positioning of lights affect site coverage Lighting tower positioning : Allow lamps to directed at sp ecific areas instead of having unused lights in non working zones. Figure 2-1. El Hyari and El Ra yes automated DSS system.

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41 CHAPTER 3 METHODOLOGY Much has been touched upon as far as the sa fety im pacts that night -time construction has on both the traveling community and the workers inside the construction area. This study is going to concentrate on a slightly different factor that is very important for the department of transportation to take notice of. This study will concentrate on the cost and productivities, in Florida between the years of 2004-2007, that are a ssociated with performing construction during the day-time as well as during the night-time. This study will focus on five different item s. These items include asphalt paving Friction Course FC-6, asphalt paving Superpave Traffic C structural course, asphalt paving Superpave Traffic D structural course, eigh teen inch prestressed concrete piles, and twenty four inch prestressed concrete piles. Since there are different types of asphalt that can be studied, this st udy will look at the two most popular structural courses of asphalt used during this tim e period as well as the most popular friction course of asphalt used. Through these four years the most popular items of structural asphalt are Superpave Asphaltic C oncrete (Traffic C) and Superpave Asphaltic Concrete (Traffic D). These two items will be quan tified individually when analyzing the data at the end of the project. The last form of asphalt that will be consid ered will be a friction course. The friction course that was most commonly used in constr uction for these time periods was Asphalt Friction Course (FC-6). Since both stru ctural courses and friction courses are used on the construction site simultaneously and have different costs it is imperative that thes e numbers be separated when analyzing the data.

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42 The second item that will be analyzed will be pile driving procedures. These items will be broken into the two most popular forms of piles driven during the four year span. During this span the two most common piles were the eighteen inch square precast concrete column and the twenty four inch square precast concrete column. This study will be performed by using the stat e of Florida Department of Transportation website. From there the researcher will access the admin page and come to the bid letting information. The researcher will then manually sc an four full years of bid letting information, sorting out the different projec ts that contain the items stated above; Superpave Asphaltic Concrete Traffic C, Superpave Asphaltic Concre te Traffic D, Asphalt Friction Course (FC-6), eighteen inch square precast concrete columns, and twenty four inch square precast concrete columns. Once these projects have been sorted they will be entered into a table, to be analyzed at a later date. This table will be separated by the work being performed and by which material is being used. For the asphalt paving procedures the bid letting date will be noted, as well as the project identification number, quant ity in tonnage of how much of the material was used, the unit cost per ton, and the contractor who performed the work. At a later date the data will be separated by individual work pr ocesses to determine the differences in costs that occurred by the time of day. The pile driving operations will be docum ented much the same way that the paving operations were documented. First the individual bid letting information will be scanned to determine the projects that cont ained pile driving operations. Once it has been determined that a specific project included pile driving, the project will be separated and the necessary data will be recorded. This data will include the bid letting data, the project identification number, the size of

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43 the individual piles being driven (eighteen inch square or twenty four inch square), the quantity (in this case the department of transportation measures thei r quantities in how many linear footage, or actual piles that were driven), the unit cost, and the contractor who performed the work. In order to receive a proper estimate of th e overall projects, the researchers will assume that one hundred projects for each of these five items will be sufficient en ough to give a realistic estimate of the entire populat ion. Once one hundred projects have been recorded the project identification numbers from all five of the separate categories will be separated and organized numerically. Once this data has been collected from the website members of the Florida department of transportation will be contacted to determine whic h projects, that have been extracted for the study, were performed during the day-time, which were performed during the night, and then which of the projects were performed during bot h the day and the night. Projects that were performed during the day as well as the nighttim e are known as hybrid projects. When these items have been determined, the data will be separated into the day, night, and hybrid project categories. These projects will be separated and averaged. Once it has been determined when each of the projects were performed the researchers will have the ability to statistical ly determine if there is a significant difference in cost between performing these construction processes during the night-time than there is to performing them during the day. From this point the differences in costs level should al so reflect the overall difference in productivity between the different times of day. It is important to mention that this study will be sensitive to the differi ng cost inflations of construction work over the four year span. Because of this, this study will attempt to normalize

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44 the data by using a construction cost index and by bringing the past unit co sts into terms of the year 2007.

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45 CHAPTER 4 RESULTS AND ANALYSIS Introduction This research project will focus on the diffe ring costs between day and night construction for paving and piling op erations. In the end it is hoped that a meaningful difference will be found in the unit prices between performing the c onstruction project duri ng the day-time and by performing the project during the night-time. This answer will aid FDOT in determining the cheapest and most productive way to pe rform a roadway construction project. This study focused on five different items within the asphalt paving and pile driving realms. All asphalt paving operations that used a FC-6 Friction Course, a Superpave Traffic C Structural Course, or a Superpave Traffic D St ructural Course were open for analysis. In addition, pile driving operations that dealt with eighteen inch pr estressed concrete columns and twenty four inch prestres sed concrete columns were also open for analysis. Once it had been determined which items were to be studied, a genera l sample size had to be decided which would correctly portray the en tire population. It was determined that each of the five items would strive for 90-100 separate pr ojects. This amount of projects would give the study a time frame between the years of (20042007), and would account for projects all around the state. This sample size would adequately be able to describe the current trends occurring throughout the state of Florida. FC-6 Friction Course Introduction The first item that was researched during the study was the Fricti on Course FC-6. Over the four year span (2004-2007), this course w ould become the most popularly used friction course. It was important for the sake of the study to choose the items that were the most

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46 prevalently used throughout the study. By using the most common materials, the study will not only achieve the largest sample size possible, it wi ll also beneficially affect the most future projects. Once all of the data had been pooled and each of the members of the department of transportation had been contacted, it came time to analyze the data and to determine any trends. While analyzing the data one thing became ve ry apparent. Despite the state of Floridas insistence on using a unit price per ton of aspha lt, many of the projects were quantified by the cubic yard method. This presented the study with a severe problem. If the study had two separate units of measurement it became difficult to compar e the overall extent of difference, due to the differing of measurement quantities. In order to remedy this, the research concentrated on performing separate analysis for e ach different sect of values. De spite the lack of uniformity the same trends should still be noticed and analyzed. Percentage Breakdown of State Projects Before delving into the differences of pr ices between day and night constructions, the study felt that it is important to provide the overall breakdown of asphalt paving Friction Course FC-6 projects throughout the state of Flor ida during this time period (Figure 4-1). This study shows that through the years of ( 2004-2007), nearly half of the asphalt paving projects (45%) occurred during the day-time while projects that include d day and night-time construction accounted for 38% of the remaining projects. In the end night-time construction only accounted for 17% of the total projects. Once the total costs of these projects have been determined it will be decided the amount of mone y that could have been saved by the department of transportation throughout th is time period by employing diffe ring forms of construction. Comparison of Differing Construction Methods The next item of business that needed to be tended to during the analysis period was determining the differences in costs that were associated with day, day & night, and night-time

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47 construction projects. While analyzing the differen ces in costs it was noticed that there were two different prevailing unit measuremen ts that were recorded by contractors. The usage of unit price per ton and unit price per cubic yard were both used by the FDOT, so both sets of data were analyzed: average unit price per ton (Figure 4-2) and average unit price pe r cubic yard (Figure 43). While looking at Figures 4-2 and 4-3 it become s apparent that nighttime construction is significantly more expensive than day-time construction. Interest ingly enough, if the work were to be performed during the day as well as the ni ght throughout the life of the project, it would be significantly cheaper than either of th e two work processes by themselves. Cost Savings The last item that was analyzed dealing with Friction Course FC-6 was the potential cost savings that were lost duri ng this time period. Throughout the life of the study there was 164,562.66 tons of asphalt Friction Course FC-6 that were laid throughout the state of Florida. Since it is already known by the study, that perf orming asphalt paving during the day and night is the most cost effective, the study decided to determine the savings impact that would occur by performing solely hybrid projects (Table 4-1). In order to find this the study multiplied the average price of day and night-time constructi on times by the total quant ity laid during the projects. This study showed that if projects were pe rformed during the day & night solely through this four year time period, there wo uld have been $3,251,035.91 less spent on roadway construction.

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48 Superpave Traffic C Structural Course Introduction The next item that was analyzed during th e study was the usage of Superpave Traffic Structural Course. Superpave Traffic C is the most popularly used structural course of asphaltic concrete throughout the state of Florida for the last four years. Because of the extensive usage of this product it becomes increasingl y important that the process of paving be as cost effective as possible. Unlike the Friction Course FC-6, there were many moreprojects that used Superpave Traffic C structural course paving, and since there was a much larg er sample size of projects to choose from, all of the projects that the researcher s decided to record were recorded in terms of unit price per ton measurements. This allowed for a greater sample size than the other items studied in the project and allowed the researcher the ability to draw stronger conclusions from the research. It should be noted that since ther e was such a large volume of Traffic C paving it was only necessary to draw da ta for two separate years. Percentage Breakdown of State Projects Much like before, this study began with a pe rcentage breakdown of the working methods of Superpave Traffic C Structural Course throughout the state (Figure 4-4). This breakdown of projects looks eerily sim ilar to the usage of Friction Course FC-6. Day-time projects accounted for 43% of the total projects and hybrid projects account for 41% of the total projects. Although there is a difference in that projects that use day and night-time construction are slightly more prevalent. The usag e of night-time projects is almost identical at 16% of the total projects.

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49 Comparison of Differing Construction Methods After determining the percentage breakdown of state projects, the next item in the study was to determine the average unit prices of da y, day & night, and night construction. Much like before the numbers were analyzed and put into graphical form (Figure 4-5). This graph shows a remarkable difference to the paving operations that include Friction Course FC-6. The study including Superpave Tra ffic C instead is predominately less expensive when performing the work during the nighttime, rather performing it during the day. Furthermore it is less expensive to perform work during the day and night than it is to solely perform it during the day. In the end it is found that the most expensive form of Superpave Traffic C asphalt paving is to perform the work solely during the day. Cost Savings The final step of the analysis of Superpave Traf fic C was to determine the effective cost savings that the state of Florid a could have witnessed during the last two year time period. This amount will be determined by multiplying the total amount (tons) of asphalt laid throughout the one hundred projects collected. This number will be multiplied by the average cost of the most cost effective time to perform the work. In this case the cheapest time pe riod is during the night. This number will be compared to the total cost that was actually incurred during the 100 projects. Once the numbers have been compared, it will show the potential cost savings (Table 4-2). By performing this hypothetical study it is noticed th at if, in this two year time period if construction had been performed during the ni ght-time there would have been savings of $10,213,454. This is an amazingly high number if you were to take into effect that this was only a two year time period. By performing construction during the most cost effective times, the state of Florida could be saving millions of dollars a year.

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50 Superpave Traffic D Structural Course Introduction The third item out of five that was studied on this research project was Superpave Traffic D Structural Course. Superpave Traffic D is th e second most popularly used asphalt structural course throughout the state of Florida for the last four years, second only behind Superpave Traffic C. It is the second structural course th at will be studied on this project and will conclude the usage of asphalt paving when the data had been analyzed (one friction course and two structural courses). The idea of this study is to co ntinue with our research to determine the most cost effective form of constructi on and continue to provide an aid to the state of Florida on cost related issues. Since Superpave Traffic D is the second most popular structural course used, there are far less projects to draw from. Therefore many of our projects suffer the ill fate that the Friction Course FC-6 projects suffered, many of the projects have differing unit price measurements. In this case the data will be di vided into two separate measurem ents, unit price per ton and unit price per metric ton. Percentage Breakdown of State Projects Continuing with the earlier tr end set by the analysis, the study will dissect the data in order to determine the current percentage breakdo wn of differing forms of construction (Figure 4-6). Looking at the pie chart, it is noticeabl e that Superpave Traffic D asphalt paving performs a greater deal of its paving operations during the day & night than its counterparts. Nearly 50% of the time Superpave Traffic D proj ects are performed during the day and the night. It is also noted that this is the lowest percentage amount of so lely day-time construction projects of either of the two asphalt paving procedures stud ied. It is also interesting to note that despite

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51 the drastic change in percentage between daytime construction and day and night construction, solely night-time construction has stayed remark ably exactly the same, in between the 15%-20% area. For some odd reason it seems that projects th at are performed with Superpave Traffic D are far more progressive than ones that ar e performed with Superpave Traffic C. Comparison of Differing Construction Methods Continuing in the fam iliar path of the study, Superpave Traffic D was analyzed in order to determine which the most cost effective form of construction is. By co mputing the average unit price per ton for each form of construction (day, day & night, and night) it can be determined which form of construction should be the most used. The following breakdown of numbers were broken down and then put into graphical form in average unit price per ton (Figure 4-7) and average unit price per metric ton (Figure 4-8). After taking time to analyze the data, one mi ght realize a few noticeable trends. First of all, much like the data shown in Figure 45, involving Superpave Traffic C, it shows a remarkable difference. But unlike the Superpave Traffic C where day-time construction is the most expensive form of constr uction, Superpave Traffic D has day & night construction as the most expensive form of construction. It is also important to realize that the numbers associated with unit price per ton and unit price per metric t on are very consistent with one another, so it can be assumed that the current conclusions are correct. It is interesting to note that while deali ng with structural cour se paving projects nighttime construction is the most cost effective meas ure. And while dealing w ith Friction Course FC6 paving projects working during the day and during the night is the most cost effective form of construction.

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52 Cost Savings Just like the other items discussed in the st udy, the next step in the analysis portion of the study is to determine the cost savings that the pr oject would incur if they were to be completed using the most cost effective form of constructi on. In this specific instance the most cost effective form of construction for Superpave Traffic D asphalt paving would to perform the project during the night-time. First, in order to determine differences in price it is important to determine the total quantity of Superpave Traffic D that is in the study. Once the total quant ity of asphalt had been determined the study decided to multiply the av erage unit price of the cheapest form of construction (night) times the total quantity of Superpave Traffic D. Once the hypothetical cost of night-time projects has been determined it can be subtracted from the total cost of the 100 sampled projects to determine the cost savings that night-time construction will create (Table 43). After looking at Table 4-3 it can be seen that if construction projects dealing with Superpave Traffic D had been paved during th e night for the years 2004-2007, the state of Florida would have saved nearly 5 million dollars. Prestressed Concrete Pilings Introduction The fourth and fifth items that were analy zed during this study were the pile driving procedures associated with eighteen inch and twenty four inch prestressed concrete pilings. Eighteen inch prestressed concrete columns are the most common form of concrete piling used throughout the state of Florida for the last four years. Twenty f our inch prestressed concrete pilings being the second most popular piling used. Despite it bei ng the most common forms of pilings, there still were the most difficult ite ms to get information on throughout the study. In

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53 entirety, the project ende d with 91 viable projects that cont ained eighteen inch or twenty four inch prestressed concrete piles. Not only was the eighteen inch pile, as well as the twenty four inch pile (mentioned in the next section), the most difficult items to attain information on. But the greater majorities of information on the subjects were differing unit m easures. For example all of Superpave Traffic C projects were measured in unit price per ton. Th e Prestressed Concrete Pilings were measured by square footage, linear footage, and by each pile dr iven. Because of this, it was a little difficult to achieve significant amount of da ta per measurement type in order to see specific trends. Percentage Breakdown of State Projects The first thing that was studi ed throughout the project was the percentage breakdown of day, day and night, and night-tim e pile driving pr ojects (Figure 4-9). With this information it would become apparent the general tendencies of the state of Florida towards pile driving procedures. After looking at Figure 4-9, it becomes apparent that it is not comm on practice to perform pile driving activities during th e night-time alone. Interesti ngly enough the only pile driving projects that were performed duri ng the night over this four year sp an, were performed in district 6 (Miami). But for the most part, the pie chart s uggests that the majority of projects are preferred to be performed during the day alone or sometim es perform pile drivi ng in a day and night method. Comparison of Differing Construction Methods Eighteen inch prestressed concrete piling The next step in the research study was to analyze the data and to determine the differences in costs associated with the diffe rent times of the day. The following data was analyzed and sorted into different graphs, that included the different sizes of piles (eighteen inch)

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54 as well as the different unit price measurement, linear foot, and each pile. The following two figures, Figure 4-10 and Figure 4-11 dealt with eighteen inch prestre ssed concrete piles that were measured in linear footage and per pile respectively. The previous two figures show that despit e the rare usage of night-time pile driving procedures, they in essence have been the most cost effective. It becomes relatively difficult to determine if the night-time projects are as eff ective as they seem in these graphs however, because there is a very small sa mple sizing of pile driving. Twenty four inch prestressed concrete piling The twenty four inch prestressed concrete pi les were also analyzed in a linear foot, each pile manner, much like the eighteen inch piles we re before. These items were analyzed in order to determine whether any significant differences could be found. The graphs representing the unit price per linear f oot (Figure 4-12) and the unit price per pile (Figure 4-13). Much like before in the analysis performe d on the eighteen inch prestressed concrete piles; night-time construction pr ovides a much more cost effec tive solution to pile driving activities. However there is a pr oblem with this conclusion. Ther e is not enough data in the area to fully conclude that night-time pile driving procedures are the more cost effective option. For the benefit of the study we will assume that the data above is correct. And we will assume the unit costs are indicativ e of the population. Cost Saving Eighteen Inch Prestressed Piles The last item of the study will c onclude with the cost savings that can be seen with more cost effective forms of constructi on. In this instance, the most cost effective form of construction for eighteen inch prestressed pi les would be to perform the pr oject during the night-time. It should be noted that this is a purel y hypothetical analysis due to the fact that there is a very small sample size of night-time constr uction. Since the sample size is so small, it could not be

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55 determined if the average unit price of night -time pile driving is a good indicator of the populations behavi or or not. First, in order to determine differences in pri ce it is important to determine the total linear footage of eighteen inch prestressed piles that we re driven. Once the total linear footage had been determined, the study decided to multiply the av erage unit price of the cheapest form of construction (night) times the tota l linear footage that had been driven over the four year period. Once the hypothetical cost of night -time projects has been determined it can be subtracted from the total cost of the 90 sampled projects to determine the cost savings that night-time construction will create (Table 4-4). After looking at Table 4-4 it can be seen that if construction projects dealing with eighteen inch prestressed piles had been driven during the night for the years 2004-2007, the state of Florida would have saved $1,248,637.97. Cost Saving Twenty Four Inch Prestressed Piles As seen with asphalt paving and eighteen in ch prestressed pile driving, the study set out to find the hypothetical costs savi ngs that could be seen by perf orming the most cost effective form of construction. In this sp ecific instance the most cost ef fective form of construction for twenty four inch prestressed pile driving would be to perform the project during the night-time. First, to determine differences in price it is important to determine the total linear footage of piles that were driven in this study. Once the total linear footage had been determined the study decided to multiply the average unit price of the cheapest form of construction (night) times the total linear footage, to determine how much would be spent if all of the twenty four inch piles that were driven, were performed at night. Once the hypothetical cost of night-time projects has been determined it can be subtracted from the total cost of the 100 sampled projects to determine the cost savings that nighttime construction will create (Table 4-5).

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56 Table 4-5 shows that if cons truction projects dealing with twenty four inch Prestressed Piles had been driven during the night for the years 2004-2007, the state of Florida would have saved $1,447,282.30. Economies of Scale Varying average quantities of projects we re used during our study. There can be a m aterially difference of unit costs that are bid on projects that have larg e amounts of work to be done in comparison to a small amount of work to be done. This data could possibly skew the findings of this study and it is impor tant to point out this fact before hand. In Table 4-6 there is data for each individual item of construction that was studied th roughout this project, as well as the average quantities and average unit prices fo r all of the projects. These numbers will be compared to one another to determine if there we re any significant differences that can be seen. Table 4-6 is set up to determine if there are a ny material differences that can be attributed to economies of scale. Economies of scale can be a rather difficult thing to determine, but what this study decided to do, was to divide the av erage quantities by the average unit prices. By doing this, it gives the research a base point for determining how much the quantity size played in the pricing for each item. In these cases, the higher the ratio means, the more likely economies of scale are present. The first item that is present on Table 4-6 is Friction Course FC-6. While looking at these numbers it appears that economies of scale could have affected th e rather low average unit cost that is associated with day & ni ght construction. Its ratio number is twice as high as the other two times of construction, it has by far the largest average qua ntity per project, and it is also the most cost effective form of construction. These numbers could possibly be infl uenced by economies of scale.

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57 The second item that was analyzed was Supe rpave Traffic C. This graph suggests that economies of scale did not affect the average unit costs of construction. In fact the most cost effective form of construction wa s the type that had the lowest average quantity per project and also it had the lowest ratio as well. This sugge sts that economies of scal e had little to do with influencing the average unit cost for night-time construction. The third item that was analyzed was Superp ave Traffic D. Much like Superpave Traffic D, the graph suggested that ni ght-time construction data was not influenced by economies of scale. In fact night-time constr uction had the lowest average qu antity, the lowest average unit price, and the lowest average ratio for all forms of construction. The last two items that were studied were the eighteen inch prestressed pile and the twenty four inch prestressed piles. The eighteen in ch prestressed piles followed in the Superpave structural course asphalt palings footsteps and showed no sign of economies of scale. Much like before with the structural paving studies, eighteen inch prestressed piles had the lowest average quantities per project, the lowest av erage prices, and the lowest ratio. It became difficult to determine if there was a significant difference of costs that could be attributed to economies of scale for twenty four inch prestressed piles however. The most cost effective form of construction had by far the hi ghest ratio, but its aver age quantity per project was strikingly similar to the different times of construction. Because of this, it is unlikely that economies of scale played a large difference in the average unit co sts of the projects.

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58 Table 4-1. Friction Course FC-6 savings during the day and night Total Quantity Average Price Total Quantity Average Price Total Cost $15,820,520.00 Day & Night 164,562.66 $76.38 $12,569,484.09 Savings $3,251,035.91 Table 4-2. Superpave Traffic C savings during the night Total quantity Average price Total quantity average price Total cost $106,080,670.78 Night 1,038,873.17 92.28 $95,867,216.13 Night savings $10,213,454.65 Table 4-3. Superpave Traffic D savings during the night Total quantity Average price Total quantity average price Total cost $65,304,654.45 Night 659,821.26 $91.90 $60,637,982.35 Night savings $4,666,672.10 Table 4-4. Eighteen inch prestresse d piles savings during the night Total Quantity Average Price Total Quantity Average Price Total Cost $19,404,352.67 Night 184,547.50 $98.38 $18,155,714.70 Night Savings $1,248,637.97 Table 4-5. Twenty four inch prestr essed piles savings during the night Total Quantity Average Price Total Quantity Average Price Total Cost $2,197,834.21 Night 60,330.00 $12.44 $750,551.90 Night Savings $1,447,282.30 Table 4-6. Economies of scale Day Day & Night Night Friction Course FC-6 Average Quantities 46,335.36 73,843.90 44,383.40 Friction Course FC-6 Average Unit Prices $107.75 $77.61 $120.58 Ratio Ton per Dollar 430.02 951.50 368.08 Superpave Traffic C Average Quantities 370,647.52 447,889.15 220,336.50 Superpave Traffic C Average Unit Prices $106.11 $105.50 $93.33

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59 Table 4-6 (Cont) Day Day & Night Night Ratio Ton per Dollar 3493.07 4245.59 2360.89 Superpave Traffic D Average Quantities 211,113.56 267,380.10 181,327.60 Superpave Traffic D Average Unit Prices $102.81 $110.74 $97.64 Ratio Ton per Dollar 2053.51 2414.41 1857.13 Eighteen Inch Prestressed Piles Average Quantity 60,887.00 117,671.50 5,989.00 Eighteen Inch Prestressed Piles Average Unit Price $110.45 $102.74 $98.38 Ratio Linear Foot Per Dollar 551.25 1145.29 60.88 Twenty Four Inch Prestressed Piles Average Quantity 20,541.00 19,656.00 20,133.00 Twenty Four Inch Prestressed Piles Average Unit Price $50.66 $46.33 $12.44 Ratio Linear Foot Per Dollar 405.50 424.25 1618.31 Day 45% Day & Night 38% Night 17% Day Day & Night Night Figure 4-1. Percentage of Asphalt Friction Course FC-6 paving projects (2004-2007)

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60 $107.75 $77.61 $120.58 $0.00 $20.00 $40.00 $60.00 $80.00 $100.00 $120.00 $140.00Unit Price per Ton Time of Day Day Friction Course FC-6 Day & Night Friction Course FC-6 Night Friction Course FC-6 Figure 4-2. Asphalt Friction C ourse FC-6 price per ton $726.71 $720.99 $924.53 0.00 200.00 400.00 600.00 800.00 1,000.00Unit Price per Cubic Yar d Time of Day Day Friction Course FC-6 Day & Night Friction Course FC-6 Night Friction Course FC-6 Figure 4-3. Asphalt Friction Course FC-6 price per cubic yard 43% 41% 16% Day Day & Night Night Figure 4-4. Percentage of Superpave Tr affic C paving projects (2006-2007)

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61 $106.11 $105.50 $93.33 $85.00 $90.00 $95.00 $100.00 $105.00 $110.00Unit Price per Ton Time of Day Day Superpave Traffic C Structural Course Day & Night Superpave Traffic C Structural Course Night Superpave Traffic C Structural Course Figure 4-5. Superpave Traffic C price per ton 32% 48% 20% Day Day & Night Night Figure 4-6. Percentage of Superp ave Traffic D Structural Course paving projects (2004-2007) $102.81 $110.74 $97.64 $90.00 $95.00 $100.00 $105.00 $110.00 $115.00Unit Price per Ton Time of Day Day Superpave Traffic D Structural Course Day & Night Superpave Traffic D Structural Course Night Superpave Traffic D Structural Course Figure 4-7. Superpave Traffic D St ructural Course price per ton

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62 $94.56 $112.69 $72.11 0.00 20.00 40.00 60.00 80.00 100.00 120.00Unit Price per Metri c Ton Time of Day Day Superpave Traffic D Structural Course Day & Night Superpave Traffic D Structural Course Night Superpave Traffic D Structural Course Figure 4-8. Superpave Traffic D Struct ural Course price per metric ton 57% 36% 7% Day Day & Night Night Figure 4-9. Percentage of conc rete piling projects (2004-2007) $110.45 $102.74 $98.38 $90.00 $95.00 $100.00 $105.00 $110.00 $115.00Unit Price per Linear Foo r Time of Day Day 18" Square Prestressed Pile Day & Night 18" Square Prestressed Pile Night 18" Square Prestressed Pile Figure 4-10. Eighteen inch prestresse d pile prices per linear foot

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63 $2,102.64 $1,682.45 $636.55 0.00 500.00 1,000.00 1,500.00 2,000.00 2,500.00Unit Price per Pil e Time of Day Day 18" Square Prestressed Pile Day & Night 18" Square Prestressed Pile Night 18" Square Prestressed Pile Figure 4-11. Eighteen inch prestressed pile prices each $46.33 $50.66 $12.44 $0.00 $10.00 $20.00 $30.00 $40.00 $50.00 $60.00Unit Price per Linear Foo t Time of Day Day 24" Square Prestressed Pile Day & Night 24" Square Prestressed Pile Night 24" Square Prestressed Pile Figure 4-12. Twenty four inch prestr essed pile prices per linear foot

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64 $2,478.58 $1,996.77 $347.22 0.00 500.00 1,000.00 1,500.00 2,000.00 2,500.00Unit Cost per Pil e Time of Day Day 24" Square Prestressed Pile Day & Night 24" Square Prestressed Pile Night 24" Square Prestressed Pile Figure 4-13. Twenty four inch prestressed pile prices each

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65 CHAPTER 5 CONCLUSION Introduction Night-time construction has been a hot bed for debate. Many critics decide that nighttime construction is necessary due to the reductio n in traffic volume. Others argue that night work construction is simply too dangerous to perf orm. The debate still wages on to this day. So far although many of the studies have been perf ormed on night-time construction have been performed on the safety impacts that night construction brings to the work environment, or what kind of lighting is adequate in the work place. This project strayed from that blue print. Instead this study focused on the cost impact that night-time construction has on a job site. The re asoning behind concentrating on the cost impact of construction was actually very simple, sin ce a night-time construction work zone area has been considered by many studies to be far more dangerous than while working during the day; it becomes very important to rationalize why night -time construction is performed at all. The thought process is that by proving some items are more productive while being performed during the night, this would give th e Florida department of trans portation reason enough to continue regulating traffic control and perfor m the work during the night-time. From the beginning, this study was performed to see if there was some sort of material difference between the costs associated with day and night-time construction. The study was constructed on the fact that th e unit cost data would be compared and contrasted to each individual type of construction to determine which item is truly the most cost effective. This study focused on finding the most cost effective form of construction and then providing a material baseline that could be followed for future projects.

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66 This study concentrated on five main items of roadway construction. These five items included asphalt Friction Course FC-6 paving, asphalt Superpave Traffic C Structural Course paving, asphalt Superpave Traffic D Structural Course paving, eighteen inch prestressed concrete pile driving, and twenty four in ch prestressed concrete pile driving. These items were the most prevalently used materials in asph alt paving and pile driving. It was felt by the researcher that these five items would have been used often e nough in order to reach a significant conclusion of pricing differences. Friction Course FC-6 The first item that was analyzed during the study was the asphalt Friction Course FC-6. This friction course was the prev alently used material while dealing with friction course paving. This study showed that the most cost effi cient projects were the ones where construction was performed during the night a nd during the day. Conversely the study showed that the least cost efficient projects were the ones where th e construction was performed solely during the night-time. Hopefully the trends will shift and hybrid constructi on will be performed more often while dealing with friction paving. Further along in the study a hypothetical situ ation was set up. This situation was set in place to prove the excessive amount of money that had been spent on other forms of construction through out the time period. In this, the total am ount of money spent on Friction Course FC-6 paving for all three types of projects were comp ared to what the cost would have been by performing the cheapest form of construction. In this case the cheapest form of construction would be by performing constructio n during the day and during the night. If all 100 projects that were analyzed had been hybrid projects (per formed during the day and night), than the department of transportation would have saved $3,302,576.44, over the four year period.

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67 Superpave Traffic C Structural Course The second item of the study was the Superpav e Traffic C Structural Course. This course is the most popularly structural course used by the FDOT over the four year time span of 20042007. By continuing in the tracks of the Friction Course FC-6 study, the specific projects were collected and analyzed to determine if there wa s a significant difference of cost. In the end it turned out that the l east expensive form of construction was diametrically opposite of Friction Course FC-6 projects. Instead projects that we re performed during the ni ght-time happened to be far less expensive to those that were perf ormed during the day-time. In fact day-time construction was the most expensive form of Superpave Traffic C Asphalt Paving. To continue with the study another hypothetical situation was cons tructed in order to determine that amount of money that could have been saved by the depart ment of transportation if all Superpave Traffic C paving operations were performed during the ni ght. The study showed that over the two year time span of projec ts there could have been savings of $10,187,276.58. Superpave Traffic D Structural Course The last paving operation that was include d in the study was the Superpave Traffic D Structural Course. Superpave Traffic D is the se cond leading material used on structural course paving operations, behind Superpave Traffic C. After analyzing the project data it was determined that the results almost entirely mirrored those of Superpave Traffic C. This s hould come as no surprise because they are both structural courses that use the same kind of app lication. The lone differenc e in this study was the fact that day and night construc tion was the most expensive form of construction for Superpave D construction projects. Night-tim e operations were the cheapest form of construction and daytime work was considered the second least expensive.

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68 In order to determine the potential impact that scheduling had on the total cost of construction another hypothetical study was constructed. Much lik e before the least expensive construction process, night-time construction was compared to the overall amount of money that was spent on the 100 projects in question. On ce the numbers had b een analyzed it was determined that there could have been po ssible savings $4,594,931.94 over the last four year span. Pile Driving The last item that was studied was the usag e of eighteen inch and twenty four inch prestressed concrete pilings. Thes e two sets of pilings were also the most popularly used over the four year time span. Once the data had been separated and analy zed it was determined that the data was in such disarray that there was not a significant difference that could be noted. This is because there were only 91 total projects over a four year time period that could be recorded. Furthermore these 91 projects that were recorded had two di fferent unit price measurements to draw from (linear foot and each pile). Becau se of this the data that was found was skewed and could not be determined. If a conclusion had to be derived from the data given, it would be that there is a significant cost savings that are associat ed with performing night-time c onstruction. In all there could possibly had been savings, for eighteen inch and twenty four inch piles, of $1,248,637.97 and 1,447,282.30 respectively. But as was stated earlier, there is such a shortage of night-time projects, that it can not be assumed that the data that was recorded can truly be indicative of the population.

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69 Recap The hypothetical study was constructed in order to show the full amount of savings that the department of transportation could be w itnessing each year due to employing more nighttime work projects. After adding up the savings this study showed that the state of Florida could have saved $20,780,705.23, from 2004-2007, by using the more cost effective measures. This near 21 million dollars only includes two years worth of Superpave Traffic C asphalt paving as well, so the amount of savings may in fact be much higher than this if all fours years of Traffic C were taken into account. It seemed that the department of transpor tation needed a reason to continue performing night-time construction. Projects were more da ngerous than during the day and illumination requirements were bothersome. There needed to be a reason other than traffic control in order to rationalize performing constructi on during the night. Now it can be argued that night-time construction is a far more cost effective proce ss than work during the day for some items of work. This proves that FDOT is better off perfor ming night-time construc tion on projects that deal with asphalt structural cour se paving. Conversely, it is in the Department of Transportations best interest to perform fricti on course paving during the day as well as during the night. By focusing on producing projects more during these time periods the department of transportation would be saving millions of dollars annually.

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70 CHAPTER 6 RECOMMENDATIONS Introduction Currently much of the research that ha s been performed in the way of night-time construction have focused on the safety impacts that night-time work z ones create. Everything from reaction time, to illumination standards, to crash rate data has been looked at and analyzed to determine the safest and most effective work zone area. The dangerous increase in work zone related accidents should continue to be studied and analyzed to determine whether having nighttime construction is feasible or not. If I were to give recommendations for certa in research projects that took into account night-time construction I would pe rsonally rather see topics stra y from the common one (safety). I would focus more on profitability and productivity differences that night-time situations create. Since it has been strongly suggested and accep ted that night-time construction creates an atmosphere that is more dangerous to drivers on the road and to the worker in the construction area, it should at least be proven to provide the contractor and the public with some economic benefits. These benefits should at least out weigh the significant safety strain that night-time construction creates. Research is needed regarding night-time construction. These ideas serve as a stepping stone to other research ideas that will hopefully improve the application of night-time construction or prove that night-t ime construction is an expendable item that produces more bad outcomes than it does good outcomes. Day vs. Night Productivity The f irst study that will be recommended will be to determine the difference in productivity between day-time and night-time c onstructions. Many people have argued that

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71 night-time construction is more productive because construction crews work in more manageable weather conditions, work in more spacious areas, a nd do not have to worry about traffic being as large of a factor. Conversely other experts argue that since the ni ght zone work area is not as well lit as it is during the day, th an construction project productivity will actually be lower than the day. It would be a very beneficial study to help prove whether ni ght-time construction is more productive or if it is less productive. Even though this would be a very beneficial study for the department of transportation to conduct it will also be a very difficult study to quantify. This would be because no two construction sites and pr ojects are the same. There will always be external factors that will get in the way of the data that needs to be recorded. In addition to this, it will also be very hard to quantify productivity rates while there are many different construction crews performing construction projects for the state. In my mind there would only be one way to perform this study. First, it would be important to concentrate on a si ngle construction crew. This way the study can compare apples to apples, meaning that it is easier to compare a construction crew against itself than it would be to compare it against a separate construction cr ew. By comparing one crew to another, it will provide inherent flaws to the st udy. What if one of the crews is more productive naturally than another? What if one crew takes a longer time to produce the work but produces a higher quality project? These items will poke holes into the study. So first it will be important to concentrate on one construction crew. This crew should be of decent size and should be one of the more popular construction crews in the state. This will allows the research to draw from a number of different projects.

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72 Secondly only a number of construction pro cesses should be studied during this study. By concentrating solely on asphalt pavi ng, the researcher will be ab le to determine the amount of time the asphalt paving crew took to lay down a cer tain tonnage of asphalt. This will allow the researcher to receive obtain able information, instead of going on a wild goose chase and breaking down the thousand of construction processes that happen on each and every construction site. State of Florida Cost Analysis The second research project that will be suggested is one that will be very similar to the research project that I presently just finished. This project will focus on the different unit cost for specific districts throughout th e state of Florida. A number of well defined construction processes that are common every day items, su ch as paving, will be studied and analyzed towards finding average unit prices. Once it is determined what the average unit pric es are for specific it ems of work, the data will be further broken down into individual work di stricts. The same analysis will take place and it will be determined what dist ricts are paying for specific type s of work to be completed. The rational behind this study is to look at th e state of Florida as a whole and determine where the unnecessary unproductive cost is coming from and eradicating it. If for some reason the study finds that one district is spending much more on average for an item of work than another item, this will allow the department of transportation the abil ity to conduct their own studies to determine what is ha ppening and why it is happening. Crash Test Data The final research suggestion that I reco mmend, will follow in the long line of past research projects. This project will concentrate on the safety impact that night-time construction has on the traveling public. The difference that this research will have on the past projects is that

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73 it will not focus on the factors th at create work zone crashes, nor it will focus on the ways to prevent crashes in the first place. Instead this project will focus on the different times of accidents that occur near work zone areas. This study will concentrate on the crash data that the department of transportation has regarding work zone accidents. Once it has been determined the amount of crashes that have occurred in areas where there are active night wo rk zones it will be analyzed to determine at what times these accidents occurred. Once these times have been analyzed it will allow the researcher to develop his or he r own hypothesis as to why this tim e period is statistically more dangerous in comparison to other time periods. In the end the researcher will either determine the probl ems that produce more crashes and develop a process that will aid in preventing crashes during th is time period. Or it will allow the researcher to develop a construction plan that will perform less work during these time periods so as to reduce the amounts of crashes that are present throughout work zone areas.

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74 REFERENCES LIST Anders, Richard. "On Road Investigati on of Fluorescent Sign Colors to Im prove Conspicuity." MS Thesis Virginia Polytechnic Ins titute. 2000. 1 June. 2008 < http://scholar.lib.vt.edu/t heses/available/etd-0922200012010036/unrestricted/Anders_ETD.pdf> Anderson, Stuart D., and Gerald L. Ullman. Reducing and Mitigating Impacts of Lane Occupancy During Construction and Maintenance Tech.No. 293. National Cooperative Highway Research Program, National Resear ch Council. Washington D.C.: Transportation Research Board, 2000. 8-26. Bryden, James A. A Procedure for Assessing a nd Planning Nighttime Highway Construction and Maintenance Tech.No. 475. National Cooperative Highway Research Program, National Research Council. Washington D.C.: Transportation Research Board, 2002. 3-24. Cottrell Jr., B. H. Final Report: Improvi ng Night Work Zone Traffic Control Virginia Transportation Research Council, Virginia Department of Transportation. Charlottesville, VA: Virginia Department of Transportation, 1999. 3-16. Ellis, Ralph, Scott Amos, and Ashish Kumar. Illumination Guidelines for Nighttime Highway Work Tech.No. 498. National Cooperative Hi ghway Research Program, National Research Council. Washington DC: Trans portation Research Board, 2003. 4-3--11. Kaisy, Ahmed A., and Khalad Nasar. Nightttime Construction Issues Revisited Transportation Research Board. Transpor tation Research, 2002. 1-25. Park, Sang-Bin, and Kimberly D. Douglas. "Facto rs of Importance for Determining Daytime Versus Nighttime Operations in Oregon." Transportation Research Record: Journal of the Transportation Research Board 1813 (2002): 2-15. Pratt, S. G., D. E. Forsbrook, and S. M. Marsh. Building Safer Work Zones: Measures to Protect Worker Injuries from Vehicles and Equipment Tech.No. Department of Health and Human Services, National Institute for Occ upational Safety and H ealth. Cincinatti, OH: National Institute for Occupational Safety and Health, 2001. 1-21. Rayes, Khaled E., and Khalied Hyari. "CONLIGHT: Lighting Design Model for Nighttime Highway Construction." Journal of C onstruction Engineering and Management 131 (2005): 1-25. Ullman, Gerald L., Melisa D. Finley, and Brooke R. Ullman. Assessing the Safety Impact of Night Work Zones in Texas Tech.No. 0-4747-1. Department of Transportation, Texas Transportation Institute. Co llege Station, TX: Texas Transportation Institute, 2004. 1-37

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75 BIOGRAPHICAL SKETCH Steven Brent Thurn was born in 1984 in Houston, Texas. Some four years later, he and his fa mily moved to Vero Beach, Florida. He atte nded high school there at Saint Edwards School. Once he graduated high school he attended the Univ ersity of Florida, where he was awarded the Bachelors of Science in Finance in Decem ber 2006. In December 2008 he was awarded the Master of Science in Building Construction.