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Strategies for Work Zone Transportation Management Plans (2020)

Chapter: Chapter 6 - Control Strategies

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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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Suggested Citation:"Chapter 6 - Control Strategies." National Academies of Sciences, Engineering, and Medicine. 2020. Strategies for Work Zone Transportation Management Plans. Washington, DC: The National Academies Press. doi: 10.17226/25929.
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110 Control Strategies “Control strategies” refers to the traffic control approaches employed to efficiently and safely accommodate road users within the work zone or the adjoining corridor, while providing adequate access to the roadway for the required construction, maintenance, or utility work to be performed. This section discusses the following control strategies: • Full road closure • Night work • Two-way traffic on one side of a divided facility (i.e., crossover) 6.1 Full Road Closure 6.1.1 Description Full road closure involves complete closure of the roadway for various time periods, providing the contractor full access to the roadway and rerouting traffic to nearby facilities. Agencies commonly use full road closures over two time durations: • Full continuous road closure. This approach involves rerouting all traffic and giving the contractor full access to the roadway with the expectation that construction time will be dramatically reduced. All operations can run continuously—24 hours a day, 7 days a week— which eliminates inefficiencies related to stopping and starting work. Full road closures can greatly reduce the duration of a project and reduce overall traffic exposure to work zones— causing greater disruption to normal travel patterns, though for shorter periods of time. • Exclusive weekend closures. Agencies use weekend closures for only one mobilization and demobilization to occur each week, but for the 55 hours or so that lanes are closed the contractor will need to operate around the clock. Using full closures on weekends helps contractors avoid peak weekday traffic; however, weekend road closures can lead to a longer project duration than a continuous road closure. 6.1.2 When to Use This strategy applies to many types of construction and maintenance activities and can be implemented on either a long-term or a short-term basis. Although some types of projects, such as complete bridge replacement, usually require long-term closure to traffic, the decision of whether and when to close a roadway is usually based on other factors, such as availability of alternative routes and the need to maintain access to abutting properties and businesses within the work zone. Full road closure may be employed in the following situations: C H A P T E R 6

Control Strategies 111 • Viable alternate routes exist and a full road closure will accelerate construction. • The project requires reduced construction time. • Agencies aim to minimize the effect on travelers. CDOT has developed a full-closure strategic analysis tool to provide staff a uniform decision process to efficiently and effectively evaluate and approve full closures and ensure the agency can successfully implement them. The tool consists of three steps, each of which requires informa- tion from the applicant and a response from CDOT traffic staff. Figure 6.1 shows and describes these following steps, and Appendix G provides the Step 1 and Step 2 worksheets: • Step 1. Applicant completes a worksheet describing the basic details of the closure scenario, including location, time, detour routes, and anticipated time savings associated with a full closure instead of phased construction with the highway remaining open. Upon receiving a completed worksheet, CDOT traffic staff uses the listed categories to evaluate the character- istics of the requested closure. Table 6.1 outlines the criteria to be considered, along with a description of how the performance of the closure scenario is to be rated in each category. The Step 1 worksheet provides CDOT staff the basis on whether the closure will be advanced to Step 2. Favorable ratings enhance the likelihood that the closure will be advanced, while Figure 6.1. Steps involved in full-closure strategic analysis tool (Credit: CDOT).

112 Strategies for Work Zone Transportation Management Plans unfavorable ratings can result in a request for more information, rejection of the proposed full closure, or significant modification to characteristics of the closure. • Step 2. CDOT traffic staff use the Step 2 added information form to request the applicant provide additional information CDOT needs to better understand implementation of the closure. Additional information may be needed to evaluate project effects on traffic and businesses, describe traffic safety conditions, or define the detour routes or regional diver- sions. Upon receipt of the additional information, CDOT traffic staff will consider the closure scenario and determine whether the closure should advance to Step 3. It is possible that the closure will be denied based on Step 2 findings. • Step 3. As Figure 6.1 shows, closures advanced by CDOT to Step 3 will be approved, even though several items may need to be addressed to ensure successful implementation. CDOT and the applicant will work together to ensure contractor accountability, monitoring of closure effects, and agency coordination. 6.1.3 Benefits The use of full road closures provides the following benefits: • Faster project delivery. • Reduced inconvenience to motorists. • Larger working area and increased productivity. • Improved project quality from the reduction in the number of joints and seams potentially needing future maintenance. • Reduced exposure for construction personnel and road users. segment by the full closure 5 Travel distance added by detour 3x travel distance or less 3–5x travel distance 5x or more travel distance 6 Local agency coordination No agency coordination required 1 agency to coordinate with 2 or more local agencies involved 7 Advance public notice >2 weeks’ notice 1–2 weeks’ notice <1 week’s notice 8 Potential for diversion out of area Well known regional travel options present Limited regional travel options present Very few good regional travel options present 9 Construction time savings >30% reduction in construction time 0–30% reduction in construction time No reduction in construction time 10 Ability to do concurrent work Other activities can be done that would have required separate, additional full-closure time Additional activities can be accomplished that would not have required separate, additional full-closure time No additional activities can be accomplished NOTE: ADT = average daily traffic. Category Favorable Fair Unfavorable 1 Impact to traffic (ADT x # of days, prorated) <50,000 50,000–100,000 >100,000 2 Functional equivalence of detour roadways Detour is the same or higher functional class as closed highway Detour route is a different functional class, but will accommodate traffic in similar fashion to closed highway Detour route is of functional class below the closed highway 3 Use of state highways as detour routes Detour route uses all state highways Detour route uses mixture of state and nonstate highways Detour route uses all nonstate highways 4 Impacts to businesses and local access There are no direct, exclusive local accesses to the closed highway Local accesses to the closed highway can be accommodated by equivalent alternate means One or more exclusive local accesses would be closed Table 6.1. CDOT full-closure rating criteria, Step 1.

Control Strategies 113 6.1.4 Expected Effectiveness The FHWA study, Full Road Closure for Work Zone Operations (2003), examined six projects that used full road closures and reported a significant reduction in project duration (Figure 6.2). According to the study, the average duration reduction resulting from the use of full road closure was 76.5 percent, compared with part-width construction using traditional maintenance of traffic. The reduced duration of full road closure projects translates into less traffic exposure, thereby eliminating crashes involving drivers and workers within the work zone. However, there may be an increase in crashes on the detour routes. 6.1.5 Crash Modification Factor No CMF is applicable for this strategy. 6.1.6 Implementation Considerations With full lane closures, agencies also need to consider other factors, such as the following: • City/county agencies and personnel often need to be convinced of the feasibility of implement- ing full road closure and the potential benefits that can be realized, compared with traditional means of performing rehabilitation under traffic. • Full-closure projects typically operate on an accelerated schedule. Before letting a project, the agency should consider the contractor’s ability to provide adequate resources (e.g., materials, equipment, crew) to maintain an accelerated pace. • The availability of detour routes to accommodate oversize, over-height, or overweight trucks is crucial and requires good communication and outreach to truck drivers and trucking associations to secure their buy-in. • Effects on business or entertainment venues can be a factor. Many projects have planned closures around events and considered adverse effects to businesses during the planning process. Such planning helps to ensure a successful project. Estimated Time Saved Figure 6.2. Estimated time saved: project days for full road closure versus estimated days with traditional maintenance of traffic (Credit: FHWA).

114 Strategies for Work Zone Transportation Management Plans • Full-closure projects are often scheduled on a 24-hour work basis, so there is potential for adverse impacts to local residents, including noise and light pollution. • Agencies and public information campaigns should encourage road users to consider public transportation alternatives on detour routes, where available. Arranging special provisions or incentives for the traveling public to use public transportation can have a marked effect on highway operations. In addition, demand-management techniques may be considered to ensure that alternative highway routes are not overloaded. Potential drawbacks of full road and weekend closures include • Significant short-term travel effects for the public. • Increased traffic congestion on other routes. • Need to construct a detour or runaround. • Adverse effect on businesses relating to trip suppression (not enough traffic). • Adverse effect on businesses on alternative routes (too much traffic). (See Section 9.2, Lighting Devices, for other nighttime work zone considerations.) 6.1.7 Design Features and Requirements The following requirements should be considered during the design of the full road closure: • Detour routes are needed during a full road closure when the original road is closed. • Detour routes should avoid creating unreasonable travel distances and delays. • Full road closures are considered successful when the detour design results in acceptable delays (either through increased travel distances or congestion). • Detour routes must have reserve capacity to be able to handle the increased traffic without creating significant delays. Agencies may need to consider improvements to the alternative route, such as temporarily removing curbside parking, adding lanes, improving traffic signals, and removing geometric bottle necks. • Extensive public outreach campaigns are needed to publicize detours and distribute detour information through a variety of media. • Special events such as holidays, sporting events, and concerts on planned road closures and alternate route options need to be considered. 6.1.8 State of the Practice Currently, state transportation departments consider full-closure opportunities on a case- by-case basis and apply engineering judgment and various factors to weigh the decision. As described in the following examples, several DOTs have let and built projects using full road closures. • South Carolina (I-385 rehabilitation). In January 2010, the South Carolina Department of Transportation (SCDOT) closed 15 mi of I-385 in Laurens County for rehabilitation. This was the first time SCDOT implemented full road closure for a nonemergency project. Doing so allowed SCDOT to complete the project in less than 8 months instead of 3 years if lanes were kept open and saved more than $34 million. The rehabilitated stretch of I-385 officially reopened on July 23, 2010—3 weeks ahead of the 8-month schedule— and under budget. • Michigan (M-10 Lodge Freeway, Fix Detroit 6 Program). During the M-10 rehabilitation project, MDOT used a bidirectional full closure to ensure the project would be completed in one season. This project was part of the Fix Detroit 6 program that coordinated six high-profile

Control Strategies 115 projects in the Detroit area during the 2002 and 2003 construction seasons. The traffic in the direction of the closure was detoured off the freeway. – Estimated duration without full closure: 6 months. – Actual duration with full closure: 53 days. • Delaware (I-95, Wilmington). To expedite construction time, the Delaware DOT (DelDOT) chose a full closure for the 6.1-mi rehabilitation project because an alternate route, I-45, had sufficient capacity. – Estimated duration without full closure: 2 years. – Actual duration with full closure: 185 days. • Kansas (Route 458 rehabilitation project, Douglas County). Route 458 between N 1050 Road and N 1116 Road was closed for 8 weeks for construction of two large culverts. A signed detour was in place during the full road closure. • California (Avenue 11 in Madera County). The California High-Speed Rail Authority closed Avenue 11 in Madera County for 18 months as part of constructing an overcrossing to eliminate an at-grade crossing and allow vehicles to travel over the high-speed rail alignment and BNSF railroad tracks. • Oregon (I-84 Banfield Freeway, Portland). The Oregon DOT used directional road closures over two consecutive weekends instead of using the traditional part-width night construction. – Estimated duration without full closure: 320 hours, or 32 nights for nighttime-only work. – Actual duration with full closure: 112 hours. • Georgia (I-285, between I-675 and I-20, Atlanta). GDOT chose to use directional full weekend road closures on the 64-lane-mile project to reduce traffic impact. The project included a public information campaign that involved media campaigns, mass mailings, community meetings, and dynamic signing. The contractors paved an average of 8 mi each weekend. Because there were no vehicles on the directional road closure, trucks did not have to wait in traffic, which ensured a constant flow of material to the worksite. – Estimated duration without full closure: 2 years. – Actual duration with full closure: 12 weekends, 6 for each direction. 6.1.9 Cost The cost to implement a full roadway closure depends on many factors, including any upgrades needed for the detoured route plus ongoing maintenance and traffic monitoring; supporting traffic control devices on both the main line and the detoured route; public out- reach that takes into consideration the extent of the influence area; and RUC. 6.1.10 Resources and References Babcock, M. W., and A. Alakshendra. Methodology to Measure the Benefits and Costs of Rural Road Closure: A Kansas Case Study, Journal of the Transportation Research Forum, Vol. 51, No. 1, Spring 2012, pp. 111–130. Del Rosario, Z., E. Kaing, B. D. Taylor, and M. Wachs. Why It Wasn’t “Carmageddon”: An Analysis of the Summer 2011 Closure of the Interstate 405 Freeway in Los Angeles, Institute of Transportation Studies, University of California at Los Angeles, August 26, 2012. DeVries, L., S. Hersey, A. Tesfaye, and D. Reeves. Full Closure Strategic Analysis, CDOT-2014-7, Colorado Department of Transportation, July 2014. FHWA. Full Road Closure for Work Zone Operations: A Cross-Cutting Study, FHWA-OP-04-009, FHWA, U.S. DOT, August, 2003. Hourdos, J., and F. Hong. TH-36 Full Closure Construction: Evaluation of Traffic Operations Alternatives, MN/RC 2010-04, Minnesota Department of Transportation, January 2010. Lee, E-L., J. T. Harvey, and D. Thomas. Integrated Design/Construction/Operations Analysis for Fast-Track Urban Freeway Reconstruction, Journal of Construction Engineering and Management, ASCE, Vol. 131 (12), 2012, pp. 1283–1291.

116 Strategies for Work Zone Transportation Management Plans McGowen, T. The Biggest Freeway Closure in the Car Capital of the World: A Brief Case Study, Journal of the Transportation Research Forum, Vol. 51, No. 1, Spring 2012, pp. 111–130. Vergara, D. Transportation Management Plan Empire/Burbank and Railroad Tracks Project, State of California Department of Transportation, July 2013. 6.2 Night Work 6.2.1 Description “Night work” refers to work performed at night (i.e., end of evening peak period to beginning or morning peak period) to minimize work zone impacts on traffic and adjacent businesses. Night work must be undertaken using the appropriate lighting devices. Refer to Section 9.2 for information on work zone lighting devices. 6.2.2 When to Use The decision of whether to perform work at night should involve a comprehensive cost- effectiveness evaluation that considers the implications of each alternative (including active night work) with respect to three key impact factors: 1. On the community and traffic (business operations, pedestrians and bicyclists, emissions, public transit, emergency services, noise effects, lighting and glare effects, traffic diversion impacts, etc.). 2. On safety (worker and motorist safety). 3. On constructability (worker efficiency, lighting plan quality, and materials and equipment availability). Night work will increase the amount of mobilization and demobilization, as it will recur every day. Night work is appropriate at project sites that have lower traffic volumes at night than during the day, when work may be easier or safer. The primary objectives of work zone traffic control are ensuring an acceptable level of safety for workers and road users, minimizing adverse effects on traffic flow and the community, and allowing the project to be completed on schedule and at an acceptable level of quality. If these objectives cannot be met during daytime construction, nighttime work may be appropriate (Antonucci et al. 2005). EVALUNITE is a simple software package, developed in 2004 for IDOT, to evaluate the suitability of nighttime work for highway projects. The software was developed using Microsoft Excel and Visual Basic for Applications. The software has a user-friendly interface that leads the user through the process of data input and running the model in a simple and clear manner. The input data are case sensitive and may differ greatly from one project to another. Therefore, most input variables are user-specified. However, default values were set for these variables in case the required information is not available to the user. This feature is useful, as it is quite likely that users will not have all the input data, especially at the planning stage of the project. In determining these default values, devel- opers attempted to identify realistic estimates for many parameters based on previous studies and the results of state DOT questionnaire surveys. Using the priorities and objectives set by the agency, the model comes up with a recommen- dation concerning the use of night shifts in highway projects. The model consists mainly of two main modules—the cost module and the effectiveness module.

Control Strategies 117 The cost module consists of three different cost models—a traffic delay model (Figure 6.3), an accident cost model (Figure 6.4), and a construction cost model (Figure 6.5). The cost modules assess all the variables that can be quantified using dollar values. The effectiveness module considers three main qualitative aspects: (1) environmental and social factors, (2) safety factors, and (3) construction-related factors. A number of factors were identified in relation to each aspect. The environmental aspects include factors such as noise disturbance, economic impacts on surrounding business, light glare to motorists, and air pollu- tion. The safety aspects relate to workers’ safety only, as the motorists’ safety is considered in the accident cost model. The construction-related factors are materials and equipment availability, freedom to plan lane closures, work quality, and temperature (Figure 6.6). By comparing the total expected cost, which includes the delay, accident, and construction costs, to the effectiveness of each alternative, agencies can use the tool to make the decision of nighttime versus daytime construction. Therefore, it is important to determine a total score for the effectiveness of each alternative (daytime and nighttime) and use that score in conjunction Figure 6.3. Traffic delay model user interface (Credit: IDOT).

118 Strategies for Work Zone Transportation Management Plans with the total cost to make the decision. Agencies can use different methods, depending on the decision-maker’s preference and the particular situation, to combine the score of each factor and its relative importance weight to find the combined score. 6.2.3 Benefits The use of night work provides the following benefits: • The effects of roadwork on traffic congestion and motorist delays can be significantly reduced or avoided. • The work zone is more flexible because traffic interference is reduced. • Quality can be achieved when sufficient lighting is provided. Cooler temperatures can enhance the quality of the concrete set at night. • Less traffic interference and longer work shifts can positively affect productivity and efficiency. • More lanes can be temporarily closed to accommodate work activities. • Lanes can be closed for a longer duration, improving efficiency and reducing completion time. Figure 6.4. Accident cost user interface (Credit: IDOT).

Control Strategies 119 6.2.4 Expected Effectiveness NCHRP Report 627: Traffic Safety Evaluation of Nighttime and Daytime Work Zones (Ullman et al. 2008) examined crash risk and type related to nighttime and daytime roadwork. The report’s findings indicated that night work does not result in a significantly greater crash risk for an individual motorist traveling through the work zone than does day work. The increases in crash risk for work operations requiring the temporary closure of travel lanes were essentially identical when performed at night or during the day. In addition, traffic crashes that occur in nighttime work zones were not necessarily more severe than those that occur in similar daytime work zones—again when compared across similar work operations. The implications of these findings are that work activities that require temporary lane closures have substantially lower total safety effects on the motoring public when the work is done at night. The lower traffic volumes at night result in a much lower number of crashes occurring over a work operation of a given duration. Although the increased risk of a crash is similar, NCHRP Report 627 also reported that differences do exist in the types of crashes that occur at nighttime and daytime work zones. For example, based on the NYSDOT work zone traffic-crash and worker-accident database, Figure 6.5. Construction cost user interface (Credit: IDOT).

120 Strategies for Work Zone Transportation Management Plans traffic crashes involving workers, construction vehicles or equipment, and construction materials and debris (both intrusion and non-intrusion crashes) comprise a greater percentage of crashes at night than during the day. Although the relative percentage of these crashes was higher at night, they were only a small proportion of the total work zone crashes in either time period. 6.2.5 Crash Modification Factor Table 6.2 shows CMFs for night work. Chapter 13 provides more information on developing work zone CMFs. 6.2.6 Implementation Considerations Scheduling construction activities during nighttime, when traffic demand is typically at its lowest, is viewed by many transportation agencies as an effective strategy to alleviate the negative effects of work zones on the traveling public. However, this argument addresses only one aspect of road construction related to traffic congestion and delay. Nighttime operations also affect other aspects that need to be considered. Some of these aspects are construction related, such as work productivity, work quality, worker safety, and construction costs; others relate to traffic Figure 6.6. Qualitative analysis user interface (Credit: IDOT).

Control Strategies 121 and worker safety, impacts on neighboring communities and businesses, air quality, and energy conservation. Therefore, agencies need to consider all these important aspects for a specific situation before they can make an informed decision on nighttime construction. 6.2.7 Design Features and Requirements Nighttime construction requires a detailed illumination plan, careful work planning and sequencing, traffic control, and nuisance-mitigation planning. Workers need to be aware of additional risks associated with night work; therefore, additional safety training may be needed before starting night work. Agencies should review the TCDs at night to ensure they are in proper condition and are visible under night conditions. Construction work zone lighting and glare specifications should identify appropriate levels of lighting based on work tasks. In addition, the agency will need practical methods for inspecting nighttime work zone lighting arrangements. 6.2.8 State of the Practice Transportation agencies routinely use nighttime construction to conduct highway maintenance and reconstruction projects. However, a literature search showed that no uniform guidelines or procedures currently exist at the national level to assist agencies in making decisions on when to employ nighttime operations. Decisions to conduct maintenance operations at night vary from state to state and transpor- tation agencies consider nighttime opportunities on a case-by-case basis, applying engineering judgment and various factors to weigh the decision. 6.2.9 Cost Night work is more expensive than equivalent daytime activities; however, the potential for greater productivity is high. Crash Type Crash Severity Facility Type Volume Range CMF Standard Error Work zone with one or more lanes closed (workers present) Nighttime All Freeways and expressways All 1.61 0.06 Nighttime Injury Freeways and expressways All 1.42 0.09 Work zone with no lanes closed (workers present) Nighttime All Freeways and expressways All 1.58 0.15 Nighttime Injury Freeways and expressways All 1.41 0.23 NOTE: Nighttime crashes were defined as those occurring from 7:00 p.m. to 6:00 a.m. The CMF calculation did not examine the difference in safety effects between the closure of a single lane and the closure of multiple lanes. Also, the CMF calculation did not consider initial lane configuration of the roadway. Because the CMFs were calculated for periods when workers were present, they may overestimate crashes if applied to all periods when the work zone is in place. It is possible that the presence of workers may induce rubbernecking and additional distractions that would increase crashes relative to times when the work zone is in place, but no construction or maintenance activities are under way. CMF = crash modification factor. Table 6.2. CMFs for night work.

122 Strategies for Work Zone Transportation Management Plans 6.2.10 Resources and References Antonucci, N. D., K. K. Hardy, J. E. Bryden, T. R. Neuman, R. Pfefer, and K. Slack. NCHRP Report 500: Guidance for Implementation of the AASHTO Strategic Highway Safety Plan, Volume 17: A Guide for Reducing Work Zone Collisions. Transportation Research Board of the National Academies, Washington, D.C., 2005. Bhagavathula, R., R. Gibbons, A. Medina, and T. Terry. Examination of the Current Practice of Lighting in Virginia: Nighttime Work Zones and Improving Safety Through the Development of Nighttime Lighting Specifications: Summary Report, FHWA/VTRC 18-R4, Virginia Department of Transportation, September 2017. Bryden, J. E., and D. J. Mace. NCHRP Report 475: A Procedure for Assessing and Planning Nighttime Highway Construction and Maintenance. TRB, National Research Council, Washington, D.C., 2002. Ellis, R. D., Jr., S. Amos, and A. Kumar. NCHRP Report 498: Illumination Guidelines for Nighttime Highway Work. Transportation Research Board of the National Academies, Washington, D.C., 2003. Elrahman, O. A. Night-Time Road Construction Operations Synthesis of Practice. New York State Department of Transportation, May 2008. Finley, M. D., G. L. Ullman, J. D. Miles, and M. P. Pratt. Studies to Assess the Impact of Nighttime Work Zone Lighting on Motorists, FHWA/TX-13/0-6641-1, Texas A&M Transportation Institute, May 2013. Freyssinier, J. P., J. D. Bullough, and M. S. Rea. Documentation of Semi-Permanent High-Mast Lighting for Construction, C-05-06. New York State Department of Transportation, September 2006. Gates, T. J., P. T. Savolainen, T. K. Datta, and P. Nannapaneni. Differences in Nighttime Luminance of Work Zone Drums with and without Steady-Burn Warning Lights. Transportation Research Record: Journal of the Transportation Research Board, No. 2258, 2011, pp. 16–24. Khaled, E-R., L. Y. Liu, L. Soibelman, and K. Hyari. Nighttime Construction: Evaluation of Lighting for Highway Construction Operations in Illinois, Report No. ITRC FR 00/01-2, Illinois Transportation Research Center, Illinois Department of Transportation, August 2003. McAvoy, D. S., K. L. Schattler, and T. K. Datta. Driving Simulator Validation for Nighttime Construction Work Zone Devices. Transportation Research Record: Journal of the Transportation Research Board, No. 2015, 2007, pp. 53-63. Nighttime Lighting Guidelines for Work Zones: A Guide for Developing a Lighting Plan for Nighttime Work Zones, American Traffic Safety Services Association, April 2013. Pesti, G., P. Wiles, R. L. (K.) Cheu, P. Songchitruksa, J. Shelton, and S. Cooner. Traffic Control Strategies for Congested Freeways and Work Zones, FHWA/TX-08/0-5326-2. Transportation Institute, Texas A&M Transportation Institute, November 2007. Rebholz, F. E., A. Al-Kaisy, K. Nassar, L. Liu, L. Soibelman, and K. El-Rayes. Developing a Decision Support Tool for Nighttime Construction in Highway Projects, ITRC FR 00/01-5, Illinois Transportation Research Center, May 2004. Shane, J. S., A. Kandil, and C. J. Schexnayder. NCHRP Report 726: A Guidebook for Nighttime Construction— Impacts on Safety, Quality, and Productivity. Transportation Research Board of the National Academies, Washington, D.C., 2012. Ullman, G. L., M. D. Finley, J. E. Bryden, R. Srinivasan, and F. M. Council. NCHRP Report 627: Traffic Safety Evaluation of Nighttime and Daytime Work Zones. Transportation Research Board of the National Academies, Washington, D.C., 2008. Ullman, G. L., M. D. Finley, and B. R. Ullman. Assessing the Safety Impacts of Active Night Work Zones in Texas, FHWA/TX-05/0-4747-1, Texas A&M Transportation Institute, October 2004. Ullman, G. L., B. R. Ullman, and M. D. Finley. Evaluating the Safety Risk of Active Night Work Zones, FHWA/ TX-05/0-4747-2, Texas Transportation Institute, Texas A&M University Transportation Institute, April 2005. Vecellio, R. L., and J. R. McCarthy. Lighting Specifications for Nighttime Construction Work Zones on Active Highways, Alabama Department of Transportation, December 2006. 6.3 Two-Way Traffic on One Side of a Divided Facility (i.e., Crossover) 6.3.1 Description This strategy involves closing one side of a divided multilane highway and moving all traffic to the other side as a two-way operation (often with a median barrier separating opposing traffic flows to prevent head-on collisions). This strategy allows work activities to occur on the closed side, separated from traffic by a significant distance. In some instances, crossovers will need to make full use of all pavement on the other side, including shoulders, to maximize traffic capacity provided.

Control Strategies 123 6.3.2 When to Use The use of crossover should be considered under the following situations: • The project has a long duration. • Opposing traffic lanes do not carry peak hour traffic. • Projects have multiple construction stages or phasing. • Worker safety is at risk. • Detour routes and adequate median or shoulder width are not available. 6.3.3 Benefits The use of median closures provides the following benefits: • A median crossover maintains traffic flow within the agency’s ROW, reducing the effects on nearby alternative routes. • A median crossover removes all traffic from the work area and allows the contractor better control of the work operation. Better-quality work may extend pavement and bridge deck service lives and reduce the frequency and extent of future maintenance and reconstruction operations. • Wider temporary lane widths resulting from median crossovers may better accommodate wide loads and could mean the difference between allowing them on site as opposed to detouring them off site. • Agencies may realize cost savings if some crossovers on freeway projects are left in place after the project is completed. Because these crossovers are designed to carry Interstate traffic, they are constructed with a high-type pavement that adds to the cost. If crossovers are left in place, this cost may be partially recovered as a cost savings to future construction. • Crossovers also leave options open for emergency construction and remain available for future operations plans, including incident management. Crossovers that remain in place after construction require traffic control to alert drivers that the crossover is not open and that using the crossover is not allowed. 6.3.4 Expected Effectiveness No studies were found that evaluated the effectiveness of median crossovers in work zones. 6.3.5 Crash Modification Factor No CMF is applicable for this strategy. 6.3.6 Implementation Considerations A median crossover requires special consideration in the planning, design, and work phases because unique operational problems (e.g., an increase in the risk of head-on crashes) can arise. The following are some considerations for designers when assessing the use of median crossovers: • Will the crossover result in restricting traffic in a reduced lane configuration longer than would a conventionally staged operation? • Can temporary lanes be constructed in the median? • Will selecting a crossover result in a shorter contract time? • Can the work be accomplished without crossover? If considering another option, will it cause an additional safety risk to TTC zone personnel?

124 Strategies for Work Zone Transportation Management Plans • Will a restricted section create difficulties for emergency vehicles when passing through or responding to accidents in, or downstream of, a crossover segment? Pullouts at 1-mi inter- vals are suggested for disabled vehicles, incident management staging, and law enforcement vehicles. Agencies should also consider using courtesy patrols for disabled vehicles and incident management. • Will a crossover add capacity? It is important to first verify that a median crossover strategy can provide adequate traffic capacity. • Will using crossovers significantly increase the project cost? Agencies will need to construct temporary pavement in the median of the roadway at both ends of the project, which adds to the overall project cost. The primary consideration when selecting crossover locations is traffic needs. A tangent section on flat terrain is the most desirable location for constructing a crossover. DOTs also need to ensure that newly created roadside hazards are adequately protected, and that work area access points near and in the crossovers are adequately designed and delineated. One disadvantage of crossover construction is that temporary pavement will be necessary at each exchange to provide entrance and exit ramp access in the direction of travel of the shifted traffic. Crossover construction is most beneficial on projects where ramp access is not mandatory. 6.3.7 Design Features and Requirements The guidance for permanent design for alignment, barriers, delineation, and illumination applies to the design for elements of temporary crossovers. The 2009 MUTCD (Section 6G.16) provides the following guidance for the design of crossovers, as well as a general crossover diagram (Figure 6H-39): • Separate tapers from lane drops from the crossovers. • Design crossovers for speeds no lower than 10 mph below the posted speed, the off-peak 85th percentile speed before the work started, or the anticipated operating speed of the roadway, unless unusual site conditions require a lower design speed. • Use a good array of channelizing devices, delineators, and full-length, properly placed pave- ment markings to provide drivers with a clearly defined travel path. • Design the crossover to accommodate all vehicular traffic, including trucks and buses. Transportation agencies may also consider the following additional design elements for installing a crossover: • Many times, the median becomes a location where waste material or other debris is deposited. There is no way to know the soil characteristics without a subsurface exploration/investigation in the crossover area, which may include power or hand borings. • The typical temporary crossover roadway has a 4:1 side slope. • A sag curve needs to be provided in the crossover between the main-line roadways. This can become more challenging when the main-line roadways are at different elevations and the median width is narrow. Drainage must flow away from each main-line roadway to prevent water or ice from accumulating. • Profile elevations are shown in each direction and on each side of the proposed roadway, typically where the pavement marking edgeline would be installed. Typically, elevations are provided at least every 50 ft along curved sections and every 100 ft along tangent sections. • As the crossover is a large impermeable area and it is generally difficult to remove surface water from the pavement quickly, agencies need to prevent concentrated flow drainage patterns.

Control Strategies 125 • Temporary barriers are used to separate the two directions of traffic. Both directions of traffic need appropriate deflection distance; if this is not possible, barriers need to be pinned as per state standards. • Temporary illumination may be considered, to improve visibility at the crossover locations. • Requirements might also address advisory speed (or speed reduction) on approach to cross- over, lane width through the crossover point, temporary pavement markings, removal of conflicting markings, and construction signs. • A systematic evaluation is needed to evaluate whether contraflow traffic using the crossover will have an adverse effect on the existing roadway safety hardware (guardrail, crash cushions, etc.). 6.3.8 State of the Practice The standards and specifications for Iowa, Washington, Montana, Connecticut, Ohio, Wisconsin, and New York include specific guidance for the design of work zone crossovers. However, only NYSDOT has a specific policy to consider median crossovers as an alternative method of work zone traffic control. 6.3.9 Cost The cost of installing a crossover depends on many factors, including soil characteristics, drainage requirements, elevation difference, and condition of the crossover lane or the need to widen lanes to adequately accommodate crossover traffic. 6.3.10 Resources and References Highway Design Manual Revision No. 85, Chapter 16—Maintenance and Protection of Traffic in Highway Work Zones (Limited Revision), Engineering Bulletin (EB 16-017), New York State Department of Transportation, April 2016. Manual on Uniform Traffic Control Devices. FHWA, U.S. DOT, 2009. http://mutcd.fhwa.dot.gov/. [MUTCD] Schurr, K. S., B. R. Gardner, and S. Rijal. Optimal Design of Work Zone Median Crossovers, NDOR Research Project Number SPR-P1(06) P581, September 2010. WisDOT. Facilities Development Manual (FDM) 11-50-5 Transportation Management Plan Process, Wisconsin Department of Transportation, May 15, 2019.

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One of the ways a state department of transportation or other transportation agency can address work zone safety and other impacts is to develop and implement a transportation management plan (TMP).

The TRB National Cooperative Highway Research Program's NCHRP Research Report 945: Strategies for Work Zone Transportation Management Plans provides a practitioner-ready guidebook on how to select and implement strategies that improve safety and traffic operations in roadway construction work zones.

Supplemental materials to the report include NCHRP Web-Only Document 276: Evaluating Strategies for Work Zone Transportation Management Plans; fact sheets on ramp meters, reversible lanes, and truck restrictions; and guidebook appendices.

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