Strategies for Work Zone Transportation Management Plans (2020)

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159 Traffic Control Devices The 2009 MUTCD, Part 6, and state manuals govern standards, guidance, and other site- specific information pertaining to installing, maintaining, and operating traffic control devices (TCDs). TCDs, such as warning signs, arrow panels, and channelizing devices, are required for all work zones, irrespective of work zone type or duration. Therefore, this guidebook does not address these common TCDs; however, the following TCDs are covered in this section: • Smart arrow boards • Lighting devices 9.1 Smart Arrow Boards 9.1.1 Description A smart arrow board is an arrow board containing data-processing capabilities to send real- time data from the field (e.g., location, direction board is facing, active/inactive display), which can then be disseminated through traveler information mechanisms such as TMCs, 511 systems, and social media dissemination systems. An example of a smart arrow board feedback to 511 and mobile units is shown in Figure 9.1. Consistent reporting of accurate, useful information about lane closures to inform travelers is a challenge for many state DOTs. Longer-duration construction and maintenance activities are typically entered into road condition reporting systems or advanced traffic management systems (ATMSs) to alert TMC operators and the traveling public. However, fast-changing and shorter-duration activities are challenging and time consuming to enter. These events are therefore not always entered to alert TMC operators or the traveling public of lane or shoulder closures. Generic reports (e.g., “intermittent lane closures from May 15 through June 30”) posted to traveler information systems, such as 511 web or mobile apps, provide limited value to travelers. Though construction and maintenance field staff often have access to up-to-date lane closure information, on-site conditions and other responsibilities make frequent reporting of this information a low priority. 9.1.2 When to Use Smart arrow boards can be used on any roadway and project type for which shoulder or lane closure is required, regardless of how long a work zone remains in place. C H A P T E R 9

160 Strategies for Work Zone Transportation Management Plans 9.1.3 Benefits The use of smart arrow boards provides the following benefits (Enterprise 2017): • Detailed, consistent, and reliable real-time information about lane closures disseminated to travelers upstream of the closure through message signs, traveler information mediums, and connected vehicle applications. • Improved situational awareness by TMC operators of real-time lane closures in the field. • Improved construction-management opportunities, including the ability to verify contractor work status to document lane closure times for use on lane-rental projects or for enforcing restricted hours or to cross-check any lane closure updates required of the contractor. • Increased archived data available for evaluation, performance management, and research to better understand work zone mobility impacts and exposure for reporting purposes, to plan future work zones, and to improve performance-based specifications. • Foundational communication technology to broadcast display status and lane closure-related information to connected and automated vehicles. • Depending on the amount of manual involvement by field staff, the potential for faster response time for maintenance needs, including times when a trailer-mounted arrow board is hit by a passing vehicle or blown out of place by strong winds, given notifications to field staff of system functionality. 9.1.4 Expected Effectiveness An evaluation of smart arrow boards was conducted by MnDOT in 2018. MnDOT piloted 20 smart arrow boards (trailer mounted and truck mounted) used by Twin Cities metro area maintenance shops, with the functionality to export status and location for stationary and mobile/rolling closures. The project then integrated the reported arrow board status information Figure 9.1. Screenshot of 511 desktop and mobile display during a stationary lane closure (Credit: MnDOT).

Traffic Control Devices 161 with the MnDOT Intelligent Roadway Information System (IRIS) and the MnDOT Condition Acquisition and Reporting System (CARS). MnDOT hired a vendor to collect and communicate arrow board data to the vendor server. At the same time, MnDOT staff programmed updates to IRIS for it to access the vendor server and process the available arrow board information. Finally, MnDOT updated CARS for it to access the arrow board information in IRIS, process the information, and generate reports for the 511 website and apps. Figure 9.1 illustrates the desktop and mobile display on 511 at 11:55 a.m. during the stationary lane closure, and the mobile worksite reports in the 511 display that is automatically updated every 1–2 minutes. The project provided the following benefits: • Detailed lane closure information disseminated through traveler information mechanisms such as 511 phone, web, and social media dissemination systems. • Regional TMC operators alerted in real time of closures so they may post messages to the appropriate signs, notifying travelers of upcoming lane closures. • Improved information for performance reporting and measurement owing to improved accuracy of lane closure information. Since the completion of the pilot, MnDOT has turned the system live. Maintenance vehicles and trailers with the arrow monitoring units installed are displaying arrow board status when activated on MnDOT’s 511 website, mobile app, and twitter feeds. 9.1.5 Crash Modification Factor A CMF is not available for this strategy. 9.1.6 Implementation Considerations The smart arrow boards must meet the requirements found in the 2009 MUTCD, Part 6F.61. There are two options for smart arrow board protocol: • Option 1, which receives data from an intermediary server, and • Option 2, in which data are polled directly from the arrow board. An Enterprise project completed a system engineering process for smart arrow boards. The results of this effort can be found at http://enterprise.prog.org/Projects/2015/workzone_ notifications_in_travelerinfo.html. 9.1.7 Design Features and Requirements In general, the smart arrow board reporting system consists of two largely independent systems, as depicted in Figure 9.2: (1) arrow boards and (2) the traveler information dissemination systems and data archives used by transportation agencies to collect, process, disseminate, and store traffic data and information for use by the traveling public and agency stakeholders. 9.1.8 State of the Practice At the time of the development of this guidebook, Iowa and Minnesota are the only two states currently deploying or planning to deploy smart arrow boards in work zones. A brief overview of their programs follows.

162 Strategies for Work Zone Transportation Management Plans 9.1.8.1 Iowa In August 2019, the Iowa DOT announced plans to adopt smart arrow board technology to collect near real-time data on the status of lane closures in construction and maintenance work zones. As a part of this, Iowa DOT took on the following responsibilities: • Work with Iowa chapter members and arrow board manufacturers to finalize specifications and test smart arrow boards before the end of 2019. • Evaluate smart arrow boards beginning in September 2019 to validate the system requirements and specifications. • Develop and publish supplemental specifications by October 2020. • Deploy smart arrow boards on Interstate projects let on or after January 20, 2021. • Deploy smart arrow boards on all Iowa DOT projects let on or after January 19, 2022. 9.1.8.2 Minnesota MnDOT developed a smart arrow board evaluation plan (Enterprise 2017) and piloted the program in 2018, as mentioned in Section 9.1.4. 9.1.9 Cost The cost for a trailer-based smart arrow board ranges between $10,000 and $12,000. The cost for a truck-mounted smart arrow board ranges between $6,000 and $8,000. 9.1.10 Resources and References Enterprise. Real-Time Integration of Arrow Board Messages into Traveler Information Systems-Evaluation Plan, Transportation Pooled Fund Study TPF-5 (231), September 2017. Iowa DOT. Smart Arrow Board Deployment Plan, Iowa Department of Transportation, August 2019. Manual on Uniform Traffic Control Devices. FHWA, U.S. DOT, 2009. http://mutcd.fhwa.dot.gov/. [MUTCD] MnDOT. Real-Time Integration of Arrow Board Messages into Traveler Information Systems: Final Requirements Testing Report, Minnesota Department of Transportation, December 2018. Virshbo, K., J. Schroeder, G. Coffee, and D. Rowe. Follow the Arrow Boards: Generating Roadwork Reports Automatically from GPS-Equipped Arrow Boards at Work Sites for Situational Awareness and Traveler Infor- mation, Presented at the Intelligent Transportation Society of America 2018 Annual Meeting, Detroit, Mich., June 4–7, 2018. Figure 9.2. Smart arrow board concept of operations (Credit: Enterprise 2017).

Traffic Control Devices 163 9.2 Lighting Devices 9.2.1 Description Roadway lighting devices enhance nighttime work zones by illuminating the work area to help drivers see TCDs, roadway alignment, pavement markings, and workers. Refer to Section 6.2 for information on night work. The two most commonly used temporary lighting systems are the following: • Portable light plant towers. This lighting consists of numerous luminaires mounted to a mast arm capable of holding the luminaires at various mounting heights. The mast arm is attached to a trailer with a generator that can be towed by a vehicle. To prevent glare, lights are aimed downward at the work—not toward the traffic—and rotated outward no greater than 30 degrees from straight down, unless the light has been designed specifically to prevent glare. • Balloon lighting. This type of lighting consists of a large balloon-type luminaire that provides a large area of evenly distributed light and is relatively glare free (Figure 9.3). Balloon lights can be mounted on slow-moving equipment or portable light towers. 9.2.2 When to Use The use of lighting devices is considered under the following scenarios: • Any nighttime applications during which a lane is taken intermittingly for construction. • Construction is undertaken on a multilane highway or Interstate. • The work zone is in a rural area with no additional highway lighting. • The project involves nighttime asphalt paving and bridge closures. 9.2.3 Benefits The provision of lighting devices provides the following benefits: • Improves work zone conspicuity and worker visibility. • Provides better guidance for drivers traveling through the work zone. Figure 9.3. Balloon lighting (Credit: NCDOT).

164 Strategies for Work Zone Transportation Management Plans • Creates uniform speeds throughout the work area. • Allows construction work to be completed safely and effectively. • Improves the overall safety of the workers and the traveling public. 9.2.4 Expected Effectiveness Improved visibility and awareness of traffic control information are expected to reduce conflicts related to drivers not being able to see TCDs well or soon enough to comply with the sign message or to follow the appropriate path. Poor visibility of TCDs often contributes to nighttime crashes, and improving drivers’ expectancy of the roadway conditions should improve safety. Work zone presence lighting has been evaluated in North Carolina, Michigan, Tennessee, Virginia, and Georgia with positive results. The average speed reduction is 5.74 mph with the highest speed reduction over 7 mph (Table 9.1). 9.2.5 Crash Modification Factor A CMF is not available for this strategy. 9.2.6 Implementation Considerations The FHWA Nighttime Lighting Guidelines for Work Zones (2013) identified the following factors when selecting the types of lighting best suited for the work zone: • Mobile work zones, such as a paving operation. If the work zone is mobile, then the length of the work activity for one night may dictate either that the lighting plan be continuous for the length of the work zone or that a mobile system be used so that the lighting moves with the various work activities. • Stationary work zones. Work duration would determine the type of lighting in this situation. A long-duration work zone could use roadway luminaires mounted on temporary poles, while shorter-duration work zones could use trailer-mounted light towers or balloon lighting at fixed locations. State Route Work Zone Speed Limit (mph) Average Speeds (mph) Average Speed Reduction (mph) With Presence Lighting Without Presence Lighting North Carolina US-17 55 57.70 51.94 5.76 Michigan US-23 55 56.92 51.27 5.65 Michigan I-94 60 65.19 57.94 7.25 Michigan I-94 60 67.78 62.82 4.96 Michigan I-94 60 68.48 62.82 5.66 Tennessee I-40 65 68.76 63.82 4.94 Tennessee I-40 70 74.76 68.89 5.87 Virginia I-64 65 67.47 60.62 6.85 Georgia I-85 60 64.76 60.05 4.71 Table 9.1. Work zone presence lighting evaluation summary.

Traffic Control Devices 165 • Glare. Glare needs to be considered from each direction and on all approaching roadways and opposing lanes of traffic, even those separated by grass medians. The goal is to minimize glare from the lighting systems for both the workers and any adjacent motorist. • Light trespass. Trespass occurs when light spills onto private property. This could be a problem in a residential area—depending on how long the lighting system is in place—and could require shielding as a preventative measure. • Backup lighting. Backup lighting must be stored on the project site and readily available for use at all times during nighttime operations. The backup systems must meet the same criteria as the primary system. 9.2.7 Design Features and Requirements Work zone illumination needs to be considered during the design phase whenever night construction would be required or allowed. This requires the following actions during the project design phase: • Determine the area to be illuminated. • Determine the work activities to be performed. • Select the type of light source. • Determine required lighting level. • Select fixture locations. • Determine luminaire wattage. • Select luminaires and aiming points. • Check design for adequacy. According to the 2009 MUTCD (Section 6F.82, Floodlights, and Section 6G.19, Temporary Traffic Control During Nighttime Hours), recommendations are for 5 foot candles of illumina- tion for general activities, 10 foot candles for activities around equipment, and 20 foot candles for activities requiring high precision and extreme care. Both of these statements in the MUTCD are identified as support conditions. NCHRP Report 498: Illumination Guidelines for Nighttime Highway Work (Ellis, Amos, and Kumar 2003) developed illumination guidelines based on work zone task illumination requirements. Level I illuminance is important in areas where the work crew is in motion, moving from spot to spot. This level of illuminance is appropriate for tasks requiring low accuracy, tasks involving slow-moving equipment, and areas where workers need to see large objects such as work zone equipment or fixed objects on the roadside. Level II illuminance is recommended for areas on or around construction equipment to provide a safer environment for the workers operating the equipment, allowing them to perform tasks that require a moderate level of accuracy. Finally, Level III illuminance is appropriate for those tasks that require a greater level of visual acuity or for tasks with a higher level of difficulty. The recommended illumination levels are summarized in Table 9.2. 9.2.8 State of the Practice Providing additional temporary lighting in work zones with the sole intent of increasing motorist safety is currently not a typical work zone practice. Lighting is typically provided in practice to illuminate the work area and increase the visibility of the workers.

166 Strategies for Work Zone Transportation Management Plans Florida, Missouri, Oregon, Washington, New York, Maryland, Mississippi, North Carolina, California, and Michigan have lighting standards for nighttime construction. Some of those standards have a limited specification about nighttime lighting and some of them, such as those in New York and North Carolina, are comprehensive regarding the practice of nighttime work zone lighting. A comparison of these limited provisions reveals that there is a lack of consensus among state DOTs on the lighting requirements for nighttime highway construction operations. Table 9.3 summarizes the specifications used by seven agencies. NCDOT has developed a typical application for work zone “presence” lighting, which is attached as Appendix H. Agency Activity or Task Specifications Caltrans All nighttime operations 10 fc FDOT Proper workmanship and inspections 5 fc GDOT All nighttime operations Average maintained horizontal illuminance 20 fc over the work area for tower lights Minimum 50,000 lumens for a tower light 460,000 lumens combined outputs of all fixtures on each tower light Between 22,000 and 50,000 lumens for machine lights IDOT All nighttime operations Minimum of 5 fc throughout the work area Minimum of 10 fc for flaggers MoDOT Active construction equipment and labor 5 fc Flaggers and other specified locations in lighting plan 0.6 fc NJDOT Tasks on and around equipment 100 lux uniformity ratio of 5:1 or less Crack filling, saw cutting, joint sealing, etc. 200 lux uniformity ratio of 5:1 or less NCDOT Tower lights 50,000–460,000 lumens 20 fc NOTE: A foot-candle (fc) is a unit of illumination equal to one lumen per square foot, or 10.764 lux. DOT = department of transportation. SOURCE: FHWA (2013). Table 9.3. Comparison of state DOT nighttime work zone lighting specifications. Examples of Tasks Illumination Level Average Minimum Maintained Illuminance All work operations areas; setup of lane or road closures, lane closure tapers, and flagging stations Level I 54 lux (5 fc) Areas on or around construction equipment; asphalt paving, milling, and concrete placement/removal Level II 108 lux (10 fc) Pavement or structural crack/pothole filling; joint repair, pavement patching/repairs; installation of signal/electrical/mechanical equipment Level III 215 lux (20 fc) NOTE: A foot-candle (fc) is a unit of illumination equal to one lumen per square foot, or 10.764 lux. SOURCE: Ellis, Amos, and Kumar (2003). Table 9.2. Recommended illumination levels by task.

Traffic Control Devices 167 9.2.9 Cost The rental cost for portable light plant towers ranges from $500 to $900 per month, and the purchase cost ranges from $9,000 to $15,000 per unit. These costs vary depending on location, type, size, height, and other factors. Based on a similar range of factors, the cost for balloon lighting normally ranges from $2,000 to $3,800 per unit. 9.2.10 Resources and References Anani, S. Work Zone Illumination Design: Guidance Strategies to Specify Appropriate Work Zone Lighting Plan. University of Wisconsin–Milwaukee, August 2015. 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-R3, Virginia Department of Transportation, September 2017. Bullough, J. D., and M. S. Rea. Final Report Optimizing Work Zone Lighting, NJ-2016-004, New Jersey Department of Transportation, October 2016. Bullough, J. D., N. P. Skinner, J. D. Snyder, and U. C. Besenecke. Nighttime Highway Construction Illumination, C-08-14, New York State Department of Transportation, August 2014. 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. https://doi.org/ 10.17226/21955. FHWA. Nighttime Lighting Guidelines for Work Zones: A Guide for Developing a Lighting Plan for Nighttime Work Zones. DTFH61-06-G-00004, American Traffic Safety Services Association, April 2013. 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 Department of Transportation, May 2013. Gambatese, J. A., and A. Jafarnejad. Use of Additional Lighting for Traffic Control and Speed Reduction in Work Zones, FHWA-OR-RD-18-10, Oregon Department of Transportation, February 2018. Huckaba, D. A. “Safer Nighttime Construction Zones Through Better Lighting: Illinois Develops and Applies Practical Guidelines,” TR News, 260, Illinois Department of Transportation, January–February 2009. Kite, S., and W. Lackey. Work Zone Traffic Control Breakout Session, North Carolina Department of Transporta- tion, February 21–22, 2019. Manual on Uniform Traffic Control Devices. FHWA, U.S. DOT, 2009. http://mutcd.fhwa.dot.gov/. [MUTCD] MDOT. Special Provision for Lighting for Night Work, Michigan Department of Transportation, APPR: December 21, 2010. Shaw, J. W., W. Bremer, Y. Han, M. V. Chitturi, A. Bill, and D. A. Noyce. Guidelines for Work Zone Designers— Illumination for Night Construction, DTHF6114H00011, FHWA, U.S. DOT, June 2018.