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Strategies for Work Zone Transportation Management Plans (2020)

Chapter: Chapter 4 - Traffic Incident Management and Enforcement Strategies

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Suggested Citation:"Chapter 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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 4 - Traffic Incident Management and Enforcement 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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Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

68 Traffic Incident Management and Enforcement Strategies This section includes various strategies to manage work zone traffic operations strategies to provide adequate enforcement of traffic regulations in work zones. The following sections are covered: • Queue warning systems • Work zone incident management plans • Temporary incident-detection and surveillance systems • Freeway service patrols • Traffic screens (a.k.a. glare screens, a.k.a. gawk screens) • Automated speed enforcement • Police enforcement 4.1 Queue Warning Systems 4.1.1 Description A QWS is a type of SWZ system that detects downstream stop-and-go traffic and alerts motorists further upstream of the congestion ahead. These systems are also referred to as “conges- tion warning systems,” “stopped traffic warning systems,” “real time traffic control systems,” “traffic merge warning systems,” and “end of queue warning systems” (EQWS). A QWS is based on algorithms and uses a series of traffic sensors to detect real-time traffic conditions (e.g., vehicle speeds, lane occupancy). When traffic speeds drop below a preset threshold, the QWS remotely activates PCMSs or warning lights on static signs to display messages to motorists upstream of the work zone beyond the maximum queue. The QWS is deactivated when the sensors indicate that the queue has dissipated and speeds are back to the preset free-flow speeds. Figure 4.1 shows the layout of a typical QWS. 4.1.2 When to Use A QWS should be considered for use under the following conditions: • Estimated queue lengths vary greatly, day by day and hour by hour, and cause 10 minutes or more of additional travel time. • Queue lengths may encroach upstream sooner than a motorist has reasonable expectations for stopped traffic, and the geometrics (terrain) may cause poor visibility for end-of-traffic queues, shorten motorists’ reaction times, and cause panic stopping. • Vertical grades, horizontal curves, or poor illumination restrict with sight distance. C H A P T E R 4

Traffic Incident Management and Enforcement Strategies 69 Figure 4.1. Queue warning system layout (Credit: MnDOT).

70 Strategies for Work Zone Transportation Management Plans • Estimated queues initiated on crossroads could cause traffic conflicts or delays on the main-line road, such as backups beyond the length of ramps, through or around turns in intersections, or other hazardous congestion situations. • The project and queue area has a history of crashes. 4.1.3 Benefits The use of QWS provides the following benefits: • Reduces primary and secondary crashes by alerting drivers to congested conditions. • Delays the onset of congestion, improving smooth and efficient traffic flow and trip reliability. • Provides environmental benefits through decreased emissions, noise, and fuel consumption. 4.1.4 Expected Effectiveness WisDOT deployed a QWS in 2017 as part of the I-43 improvement project in Manitowoc County. A crash analysis conducted with and without the QWS reported a 15 percent reduction in queuing-related crashes and a 63 percent reduction in injury crashes. The QWS reduced queue- related work zone crash costs by 13 percent. The change in average speeds as drivers reacted to the first PCMS varied for each scenario: STOPPED TRAFFIC AHEAD and SLOW TRAFFIC AHEAD resulted in an increase of 3.8 mph and a decrease of 45.6 mph, respectively. However, many variables influenced these results, including visible brake lights downstream, proximity to the start of the lane closure, the number of PCMS boards activated and the corresponding messages, and the location where vehicle speeds were measured. KSDOT used a QWS in conjunction with the Five-Bridges construction project located along route I-235 in Wichita between Spring 2016 and Fall 2017. Although the QWS was not operating as intended until early June 2016, it operated within specification nearly 100 percent of the 2017 season. Results included a 59.8 percent reduction in total crashes and 70.1 percent reduction in rear-end crashes. Estimated reduced crash cost was $8,700 per day. TxDOT used a QWS in combination with TRSs to reduce the risk of crashes on the I-35 expansion project and reported the following results: • An 18 percent to 45 percent reduction in crashes compared with an estimate of crashes if the system had not been deployed. • Savings of between $1.4 million and $1.8 million in crash costs (savings of $6,600–$10,000 per night of deployment). Figure 4.2 shows the QWS deployment plan used on the I-35 expansion project. TxDOT also deployed a QWS on IH-610 and US-59 in Houston during the 2008 construction season and saw a 2 percent to 7 percent reduction in sudden braking and a 3 percent to 5 percent reduction in forced lane changes at these locations (Pesti et al. 2008). The Illinois DOT (IDOT) deployed a QWS on two projects with the following results: • I-70/I-57 interchange in Effingham—a 14 percent decrease in queuing crashes and an 11 percent reduction in injury crashes, despite a 52 percent increase in the number of days temporary lane closures were implemented during the evaluation. • I-55 from I-70 to IL-140 in southern Illinois—13.8 percent reduction in rear-end crashes with QWS in place, even with 25.4 percent more traffic exposure.

Traffic Incident Management and Enforcement Strategies 71 4.1.5 Crash Modification Factor Table 4.1 shows the CMF for a work zone QWS. Chapter 13 provides more information on developing WZCMFs. 4.1.6 Implementation Considerations There are many different contracting options for including QWS in work zone projects. Some projects may include the QWS component as a bid item in an overall construction project and other projects may retain a QWS vendor with a stand-alone contract. Figure 4.2. Example QWS deployment plan (Credit: TxDOT).

72 Strategies for Work Zone Transportation Management Plans Several IDOT districts have on-call contracts to deploy QWS for shorter-duration work zones, lasting less than 2 weeks, that may have queues but do not have a project budget large enough to support the SWZ deployment. MDOT notes the importance of calling out specific pay items (e.g., PCMS, sensors, cameras) when developing a contract so modifications to the system can be made throughout the project. 4.1.7 Design Features and Requirements QWSs typically involve three basic components: (1) detection devices (video cameras, microwave or Doppler radar, infrared, etc.) placed upstream of the work zone to monitor and measure the speeds of approaching vehicles; (2) a server to receive and analyze the sensor data in real time and activate a message; and (3) PCMSs located upstream of the work zone to display a warning message. When a PCMS detects slow or stopped traffic, it displays a predesigned warning message to alert the driver of the condition. Example messages posted on PCMSs for different scenarios are shown in Table 4.2. When the QWS detects no queue, the PCMS displays a more generic ROAD WORK AHEAD message. Agencies have also placed portable rumble strips in the travel lanes upstream of the merging taper to provide tactile, audible, and visual alerts as drivers approach the lane closure. At a minimum, the QWS must be able to • Detect vehicle speed and volume over a user-defined interval (ranging from 30 seconds up to 10 minutes) and sense queuing of traffic in up to five lanes in one direction simultaneously. Crash Type Crash Severity Facility Type Volume Range (AADT) CMF Standard Error Nighttime All Rural Interstate where queues were expected 55,000–110,000 0.559 0.255 Nighttime All Rural Interstate when queues were actually present 55,000–110,000 0.468 0.301 Nighttime All Rural Interstate when queues were not actually present 55,000–110,000 0.717 (not significant) 0.353 NOTE: The CMFs listed were developed through an empirical Bayes analysis using 234 control and 216 treatment nights of lane closures. The sample sizes were small in both expected and actual crashes because less than 1 year’s worth of nighttime lane closures from each condition was available for analysis. AADT = annual average daily traffic; CMF = crash modification factor; QWS = queue warning system. Table 4.1. CMFs for QWS. Scenario Example Message Speed Threshold Free Flow CAUTION/ ROAD WORK AHEAD 55 mph Slow Traffic SLOW TRAFFIC AHEAD/ PREPARE TO STOP 40–45 mph Stopped Traffic TRAFFIC STOPPED AHEAD/ PREPARE TO STOP 15–25 mph NOTE: PCMS = portable changeable message sign; QWS = queue warning system. Table 4.2. PCMS messages for QWS.

Traffic Incident Management and Enforcement Strategies 73 • Automatically set the PCMS message sequences to reflect the current traffic-flow status to the nearest minute, update every 60 seconds, or update to a customized frequency defined by the engineer. • Have default queue level thresholds (normal, slowing, stopped) based on any combination of vehicle speed, volume, or density based on conditions in the slowest or most congested lane. • Use e-mail or text to alert contractor and agency personnel, including TMC or traffic opera- tions center (TOC) staff, whenever the default queue level changes from normal to slowing or stopped. Figure 4.2 provides an example QWS deployment plan and system logic used on the I-35 project in Texas. When preset detector thresholds are met at the first detector (closest to the work area), the first PCMS notifies travelers of slowed or stopped traffic and distance to the condition. Subsequent PCMSs (farther from the work area) also notify travelers of slowed or stopped traffic and approximate distance to the condition. 4.1.8 State of the Practice QWS is one of the technology applications promoted by the FHWA’s SWZ, during Round 3 of the FHWA EDC initiative. Many resources, including bid specifications, deployment plans, and case studies, are available on the National Work Zone Safety Information Clearinghouse (https://www.workzonesafety.org/swz/). Colorado, Illinois, Iowa, Michigan, Minnesota, Ohio, Texas, and Wisconsin use QWSs as a standard practice; thus, these states have mature systems that generate accurate, dependable results. As part of the FHWA Accelerated Innovation Deployment grant, WisDOT developed a QWS decision-support system to help designers and traffic engineers determine if a QWS is needed for a project. The intent of the system is to identify candidate work zones for QWS early on in the scoping and TMP phase of the project. The decision-support system is integrated with the Wisconsin TMP (WisTMP) System. Maintained by the University of Wisconsin Traffic Operations and Safety Laboratory (UW-TOPS lab), the WisTMP system is an online program used to create, approve, monitor, and update TMPs. The decision-support system integrates data from disparate WisDOT sources, such as the WisTMP, traffic volumes, crashes, and the photolog, to provide information on potential queues and delays, the presence of horizontal and vertical curves, and entrance and exit ramps within and in the vicinity of work zones. Figure 4.3 is an image of the decision-support system. 4.1.9 Cost The cost to deploy a smart work zone such as the QWS depends on the project duration and the number of devices (e.g., message boards, traffic sensors, speed trailers, cameras) used. In general, the rental cost is the same for a PCMS or a traffic sensor or camera: approximately $1,000 per week. For longer-duration projects, the rental costs can be substantially lower. Based on 2018 rental prices, MnDOT reported the cost estimate for a QWS project using 2 PCMSs and 6 sensors at $7,000 per week or $13,000 per month or $58,000 for 6 months. The TxDOT Smart Work Zone Guidelines (2018) reported a cost of $104,160 for a QWS deployment in 2017 that used 1 PCMS and 4 sensors for 70 days (∼0.7 percent of total con- struction costs).

74 Strategies for Work Zone Transportation Management Plans Cost estimates for a QWS deployed by WisDOT in 2016 on two separate bridge construction projects were as follows: • 6 PCMSs, 14 sensors for $826 per day (total for 77 days = $63,602). • 16 PCMSs, 22 sensors for $725 per day (total for 202 days = $146,450). 4.1.10 Resources and References FHWA Every Day Counts (EDC) Initiative: Smarter Work Zones, Technology Applications: Queue Warning web page. https://www.workzonesafety.org/swz/swztechnology-application/types-of-applications/queue- warning/. McCoy, P. T., and G. Pesti. Effect of Condition-Responsive, Reduced-Speed-Ahead Messages on Speeds in Advance of Work Zones on Rural Interstate Highways. Presented at 80th Annual Meeting of the Transporta- tion Research Board, Washington, D. C., 2001. Morris, T., J. A. Schwach, and P. G. Michalopoulos. Low-Cost Portable Video-Based Queue Detection for Work- Zone Safety, Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, CTS Report No. 11-02, January 2011. 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, Texas Department of Transportation and FHWA, October 2008. Figure 4.3. QWS decision-support tool (Credit: WisDOT).

Traffic Incident Management and Enforcement Strategies 75 Queue Warning Systems in Work Zones: Summary of Uses and Benefits, ENTERPRISE Transportation Pooled Fund Study TPF-5 (231), June 2014. TxDOT. Smart Work Zone Guidelines: Design Guidelines for Deployment of Work Zone Intelligent Transportation Systems (ITS), Texas Department of Transportation, October 2018. Ullman, G., and J. Schroeder. Mitigating Work Zone Safety and Mobility Challenges through Intelligent Trans- portation Systems: Case Studies, FHWA-HOP-14-007, FHWA, U.S. DOT, January 2014. Ullman, G. L., V. Iragavarapu, and R. E. Brydia. Safety Effects of the Portable End-of-Queue Warning System Deployments at Texas Work Zones. Transportation Research Record: Journal of the Transportation Research Board, No. 2555, 2016, pp. 46–52. Ullman, G., J. Schroeder, and D. Gopalakrishna. Use of Technology and Data for Effective Work Zone Management: Work Zone ITS Implementation Guide, FHWA-HOP-14-008, FHWA, U.S. DOT, January 2014. Wiles, P. B., S. A. Cooner, Y. Rathod, and D. G. Wallace. Advance Warning of Stopped Traffic on Freeways: Field Studies of Congestion Warning Signs, FHWA/TX-05/0-4413-2, Texas Department of Transportation and FHWA, March 2005. 4.2 Work Zone Incident Management Plans 4.2.1 Description A work zone Incident Management Plan (IMP) is one element of the traffic operations component of the TMP; “IMP” refers to strategies used to help the contractor and the agency respond appropriately to incidents during construction within a reasonable time frame and maintain safe traffic flow through the work zone. 4.2.2 When to Use Long-term, complex reconstruction projects necessitate a comprehensive effort with pro- cedures and processes to support the project. The complexity of the IMP depends on the complexity and duration of the project, as well as its effects in the corridor or network. DOTs require complete IMP documents for significant projects. Short-term projects on lower-volume roads may simply require a meeting or ongoing coordination with the appropriate local or regional emergency response agencies. 4.2.3 Benefits A work zone IMP provides the following benefits: • Reduces the amount of time to detect, verify, and respond to an incident. • Decreases time required for appropriate response personnel and equipment to respond to the scene. • Facilitates management of the response apparatus and personnel on site to minimize the capacity loss associated with the incident and the response equipment. • Provides travelers upstream of the incident with rapid notification, encourages a decrease in traffic demand entering the incident area, and reduces driver frustration. 4.2.4 Expected Effectiveness Prompt detection and clearance of traffic incidents in work zones helps reduce secondary crashes and delay. Preparing a work zone traffic incident management plan and using strategies that improve detection, verification, and response, along with clearance of crashes, mechanical failures, and other incidents in work zones and on detour routes, can benefit safety and mobility.

76 Strategies for Work Zone Transportation Management Plans Figure 4.4 illustrates the timeline of a typical incident that might be a crash affecting one or more travel lanes. The steps shown represent the typical sequence for most moderate-to-serious incidents. 4.2.5 Crash Modification Factor No CMF is applicable for this strategy. 4.2.6 Implementation Considerations As with any project, the minimum requirement is to identify whether a program exists and determine the role of the contractor in implementing that program. Project staff or the contractor should also contact appropriate response agencies in the corridor to discuss the proposed work zone, identify their concerns, and agree to procedures and strategies that will support traffic incident management. Communication and coordination are essential for any work zone. On more complex projects, this coordination will become more formalized and involve more stakeholders. It will also necessitate a greater commitment of time and resources on the part of the contractor. For a project with multiple phases, it may be necessary to develop a plan for each project phase. The procedures and recommended strategies should be documented and distributed to all response agencies and construction personnel. Budget strategies that require implementation (e.g., signing, intelligent transportation system devices, traffic management center, service patrol) should be planned and implemented at the start of the project. Roadway Clearance Clearance Response Verification Detection Recovery Figure 4.4. Timeline of a typical incident that might be a crash affecting one or more travel lanes.

Traffic Incident Management and Enforcement Strategies 77 Regular training and follow-up sessions are necessary to ensure all agencies and construction personnel are familiar with plan procedures. 4.2.7 Design Features and Requirements Agencies need to ensure that developing an IMP is a collaborative effort with the project owner and emergency response agencies; the IMP either can be a stand-alone document or incorporated into the TMP. The following is a standard format for an IMP table of contents: • Project description and map (if an IMP is not incorporated in the TMP). • Emergency contact information. Identifies contact information for contract personnel, project owners, and emergency response agencies responsible for responding to or desig- nating response for incidents. • Existing protocols and agreements. Each agency responding to an incident in the project area has specific priorities and responsibilities. Some of these roles may overlap, and the priorities of some agencies may affect the ability of other agencies to perform their duties. Discussing and documenting these roles and responsibilities during the planning phase of traffic incident management will minimize the probability of conflicts or confusion during an actual incident. • Procedures for communicating during an incident (communication flowchart). In the event of an incident, it is essential that response agencies know how to contact one another to coordinate and confirm the most effective use of resources. • Incident-level definitions. Incident levels are defined by the extent and duration of the anticipated effect on the roadway. Defining levels will help agencies identify appropriate actions and responses to the anticipated level of impact. The 2009 MUTCD (Section 6I.02, 6I.03, and 6I.04) divides incidents into three general classes based on duration: (1) major (>2 hours), (2) intermediate (30 minutes to 2 hours), and (2) minor (<30 minutes). Agencies can use these general criteria for classifying incident levels as a beginning point for determin- ing appropriate levels of responses. • Incident-detection, response, and clearance strategies. Once the appropriate level of response is determined for the work zone, the next step is to identify and evaluate candi- date strategies for detecting, responding to, and clearing incidents from the roadway (e.g., temporary incident-detection systems, roving courtesy/service patrols, emergency turn- around access). • Identify alternative emergency routes. Choose project-specific alternate routes and develop an alternative route map. • Disseminate traveler information. Identify strategies (PCMSs, traffic alerts, websites, TMC, etc.) to facilitate timely information dissemination about work zone incidents. 4.2.8 State of the Practice WisDOT has developed templates for IMPs, which are attached as appendices: • Appendix E1 presents one example of a WisDOT IMP. • Appendix E2 presents a second example of a WisDOT IMP. 4.2.9 Cost Work zone IMP is part of the TMP and therefore has no separate cost associated with it. 4.2.10 Resources and References Balke, K. Traffic Incident Management in Construction and Maintenance Work Zones. FHWA-HOP-08-056, FHWA, U.S. DOT, January 2009.

78 Strategies for Work Zone Transportation Management Plans Bremer, W., D. A. Noyce, J. W. Shaw, M. V. Chitturi, and A. Bill. Guidelines for Work Zone Designers—Positive Protection. DTHF6114H00011, FHWA, U.S. DOT, May 2019. Charles, P., and R. Higgins. Successful Incident Management on a Major Reconstruction Project, Pacific Motorway Project, Queensland Australia, University of Queensland, Australia, November 2001. CDOT. Guidelines for Developing Traffic Incident Management Plans for Work Zones, Colorado Department of Transportation, 2008. Dougald, L. E., N. J. Goodall, and R. Venkatanarayana. Traffic Incident Management Quick Clearance Guidance and Implications, FHWA/VTRC 16-R9, FHWA, Virginia Department of Transportation, February 2016. Federal Emergency Management Agency. U.S. Fire Administration Traffic Incident Management Systems, FA-330, April 2008. FHWA. Intelligent Transportation Systems in Work Zones: A Case Study—Work Zone Traffic and Incident Management System, Keeping Traffic Moving During Reconstruction of the Big I, a Major Interstate-Interstate Interchange in Albuquerque, FHWA-OP-04-072, U.S. DOT, January 2004. Horowitz, A. J., and Xia J. Guidebook on Incident Management Planning in Work Zones. University of Wisconsin– Milwaukee. September 1, 2005. I-95 Corridor Coalition. Traffic Incident Management (TIM) Best Practices Report, March 2010. Marquess, A., P. Desai, G. Havinoviski, and C. Heise. Safety Service Patrol Priorities and Best Practices, FHWA- HOP-16-047, FHWA, U.S. DOT, April 2017. Manual on Uniform Traffic Control Devices. FHWA, U.S. DOT, 2009. http://mutcd.fhwa.dot.gov/. [MUTCD] Noyes, P. B. Mainstreaming Incident Management in Design-Build: The T-REX Experience. Colorado Department of Transportation, 2001. Pennsylvania State Transportation Advisory Committee. Traffic Incident Management Final Report, Pennsylvania Department of Transportation, February 2014. 4.3 Temporary Incident-Detection and Surveillance Systems 4.3.1 Description A temporary incident-detection and surveillance system uses sensors or video to detect crashes and other incident conditions within a work zone and then communicates that infor- mation to a local TMC or to emergency response agencies (Figure 4.5). The alerts are then confirmed remotely using live streaming video, photographs, or on-site personnel. Agencies can use this system to provide responders critical information to help them bring necessary equipment, identify how best to approach the incident, and take any additional precautions that might be needed to protect themselves and the public. 4.3.2 When to Use Temporary incident-detection and surveillance systems should be considered for use under the following conditions: • Long-term project duration in urban areas. • Presence of a permanent intelligent transportation system (ITS) deployment, a TMC, or both. • High public exposure or traffic delay. • Projects with multiple construction stages or phasing. • Frequent lane or ramp closures expected. • Frequent crash history within the work zone corridor. • Work-zone corridor at or near capacity. 4.3.3 Benefits Temporary incident-detection and surveillance systems provide the following benefits: • Improving the situational awareness of emergency responders will reduce the time to detect, respond to, and clear incidents.

Traffic Incident Management and Enforcement Strategies 79 • Provides details about each disabled vehicle or crash site (e.g., size of vehicle, orientation of vehicle, fuel or cargo spills) so the appropriate response vehicles and equipment can be deployed effectively. • Reduces the probability of a secondary incident that may have severe consequences. 4.3.4 Expected Effectiveness No recent studies were found that evaluated the effectiveness of temporary incident-detection and surveillance systems. However, a 2004 FHWA case study reported that using ITS in work zones helped reduce incident response time by 20 minutes. 4.3.5 Crash Modification Factor No CMF is applicable for this strategy. Figure 4.5. Temporary incident-detection and surveillance system layout (Credit: TxDOT).

80 Strategies for Work Zone Transportation Management Plans 4.3.6 Implementation Considerations The following aspects should be considered for deployment of temporary incident-detection and surveillance systems: • Agencies need a reliable means of communication to transmit data, as geography or infra- structure may limit communication options. • A TMC needs to be in place or established. • An individual is required to monitor video surveillance cameras, usually at a traffic manage- ment center. As construction phasing progresses, agencies may need to relocate cameras and communications infrastructure. • The system should be connected to a TMC that can contact the appropriate agencies to respond to incidents and notify the public. • Personnel with special technical skills are required to keep cameras and communications systems operational. • The system can be costly to install and maintain during the life of a construction project. 4.3.7 Design Features and Requirements Incident-detection and surveillance systems typically include the following: • Multiple closed circuit television (CCTV) cameras with pan, tilt, and zoom capabilities to ensure comprehensive coverage of the work zone and the approaches to it. CCTVs will typically be placed in areas of high risk, such as the approach to a taper or crossover. High-risk areas can also include locations where the designer anticipates motorists taking evasive or aggressive action. • Format and frequency requirements for archive data transmission to a TMC. • 24/7 system operation hours. • Live alerts to various agencies or a TMC. • Error detection and correction mechanisms. • Automated continuous data-collection systems (if performance measures are needed or TMCs need situational awareness). 4.3.8 State of the Practice Colorado, California, Massachusetts, Minnesota, Texas, and Virginia have used temporary incident-detection and surveillance systems on long-term construction projects. 4.3.8.1 Colorado The Gap is an 18-mi stretch of I-25 in Colorado, running from south of Castle Rock to Monument. It is the only four-lane section of I-25, connecting Colorado’s two largest cities— Denver and Colorado Springs. On average, nearly 80,000 vehicles travel the I-25 South Gap corridor daily with delays and crashes a common occurrence. To address safety concerns during construction, CDOT deployed an on-site TOC that uses cameras, signs, and vehicle-detection devices to help with incident management. Typically, construction projects feed into the larger TOCs across the state, but this project is the first ever in Colorado to have its own on-site TOC. The TOC is staffed 24/7 to monitor current roadway conditions and quickly respond, aiming to reduce congestion by suggesting drivers take alternate routes when incidents occur. Construction on the $350 million project, which is currently the longest construction zone in the state, began in Fall 2018; project completion is scheduled for 2022. The TOC is shown in Figure 4.6.

Traffic Incident Management and Enforcement Strategies 81 4.3.8.2 Work Zone Accident Reduction Deployment System MnDOT led the launch of the Work Zone Accident Reduction Deployment (WZARD) system in January 2012 along eastbound I-94 between TH 15 in Saint Cloud to TH 101 in Rogers, totaling 34 mi. The system was designed so that when a snow plow or maintenance vehicle equipped with automatic vehicle location (AVL) came within a certain geofenced area, the central system received a signal to determine whether to disseminate a preprogrammed message. For example, if an AVL-equipped snow plow was active within a certain area, the system would post SNOW PLOW AHEAD USE CAUTION on the message signs within that area (Figure 4.7). WZARD was designed in response to snow plow operators and maintenance personnel expressing concern for their safety and that of other road users when plowing or maintenance was under way. The primary purpose of WZARD was to improve safety for snow, ice, and other maintenance operations. WZARD provided the following benefits: • Automated geofenced AVL improved traffic safety during snow and ice operations and other work zone activities by informing vehicle operators of work vehicles ahead. Figure 4.6. I-25 Gap project operation center (Credit: CDOT). Figure 4.7. MnDOT WZARD system (Credit: MnDOT).

82 Strategies for Work Zone Transportation Management Plans • Travelers along I-94 outside of the metro area received crucial traveler information, including advance warning of work zone activities and traffic incidents. • Planned and currently installed roadside technologies were integrated with automated systems to streamline traveler information and reduce MnDOT and Minnesota State Patrol vehicle crashes or conflicts on the corridor. 4.3.9 Cost The cost to deploy an SWZ, such as a temporary incident-detection system, will depend on project duration and the number of devices (e.g., message boards, traffic sensors, speed trailers, cameras) used. In general, the rental cost is the same for a PCMS or a traffic sensor or camera—approximately $1,000 per week. For longer-duration projects, the rental costs can be substantially lower. TxDOT Smart Work Zone Guidelines (2018) reported the following costs for temporary incident-detection and surveillance systems: • $2,395,816 (1 percent of total construction cost) for 8 PCMSs, 14 sensors, 8 cameras, and 8 trailers deployed for 76 months (∼ $32,000/month). • $1,574,058 (1 percent of total construction cost) for 9 PCMSs, 14 sensors, 9 cameras, and 9 trailers deployed for 46 months (∼ $34,000/month). • $306,616.75 (2 percent of total construction cost) for 3 trailers, 9 sensors, 3 cameras, and 3 PCMSs with modem deployed for 20 months (∼ $15,000/month). 4.3.10 Resources and References Balke, K. Traffic Incident Management in Construction and Maintenance Work Zones, FHWA-HOP-08-056, FHWA, U.S. DOT, January 2009. CDOT Guidelines for Developing Traffic Incident Management Plans for Work Zones, Colorado Department of Transportation, 2008. Charles, P, and R. Higgins. Successful Incident Management on a Major Reconstruction Project, Pacific Motorway Project, Queensland Australia, University of Queensland, Australia, November 2001. Dougald, L. E., N. J. Goodall, and R. Venkatanarayana Traffic Incident Management Quick Clearance Guidance and Implications, FHWA/VTRC 16-R9, FHWA, Virginia Department of Transportation, February 2016. FEMA. U.S. Fire Administration Traffic Incident Management Systems, FA-30, April 2008. FHWA. Intelligent Transportation Systems in Work Zones: A Case Study—Work Zone Traffic and Incident Management System, Keeping Traffic Moving During Reconstruction of the Big I, a Major Interstate-Interstate Interchange in Albuquerque, FHWA-OP-04-072, U.S. DOT, January 2004. Horowitz, A. J., and Xia J. Guidebook on Incident Management Planning in Work Zones. University of Wisconsin– Milwaukee. September 1, 2005. I-95 Corridor Coalition. Traffic Incident Management (TIM) Best Practices Report, March 2010. Noyes, P. B. Mainstreaming Incident Management in Design-Build: The T-REX Experience. Colorado Department of Transportation, 2001. Pennsylvania State Transportation Advisory Committee. Traffic Incident Management Final Report, Pennsylvania Department of Transportation, February 2014. TxDOT. Smart Work Zone Guidelines: Design Guidelines for Deployment of Work Zone Intelligent Transportation Systems (ITS), Texas Department of Transportation, October 2018. 4.4 Freeway Service Patrols 4.4.1 Description Freeway service patrols (FSPs) use specially equipped vehicles to provide emergency repairs and rapid clearance of stalled or disabled vehicles from the roadway. Vehicles can be positioned at either strategic locations or rove in the traffic stream.

Traffic Incident Management and Enforcement Strategies 83 4.4.2 When to Use Tow/freeway service patrols are best suited for use in the following situations: • Long project duration. • High public exposure and traffic volume. • Locations where incidents can create significant delays. • Locations where shoulder-width reductions or closures are expected. • Locations with a history of high crashes. 4.4.3 Benefits The use of FSPs provides the following benefits: • Reduce roadway-clearance time. Decreases the time between the first recordable awareness of the incident by a responsible agency and the first confirmation that all lanes are available for traffic flow. • Reduce incident-clearance time. Lessens the time between the first recordable awareness of the incident by a responsible agency and the time that the last responder has left the scene. • Reduce the number of secondary incidents. Decreases the number of crashes that occur after the primary crash, either within the original incident scene or within the queue in either direction, caused by the original incident. • Reduce nonrecurring traffic congestion and improve travel time reliability. Removes debris, disabled vehicles, and minor crashes from the travel portion of the roadway quickly and safely. • Improve highway safety for responders and motorists. Provides proper traffic control to support a safe incident work area for responders and victims. • Provide timely and accurate information to the TMC. Allows staff to activate traveler information devices and warn motorists when they are approaching an incident or closure; to prompt systems such as 511, websites, and media; and to alert motorists of the current road conditions, lane or road closures, diversions, and any delays before their departure. 4.4.4 Expected Effectiveness An evaluation of the arterial service patrol deployed in Missouri during the 2008 I-64 con- struction project demonstrated the following summary of findings (Ryan et al., 2010): • A conservative benefit–cost ratio was 8.3:1. • 183 secondary crashes were prevented per year. • $1,034,000 in annual congestion cost was saved. 4.4.5 Crash Modification Factor No CMF is applicable for this strategy. 4.4.6 Implementation Considerations Clear communication between the TMC and the tow/freeway service patrollers is essential. In addition, both entities need to understand the other’s job functions and needs. The patrollers are often the agency representative on the scene in the incident-command setting and relay the requests for agency resources from the incident commander to the TMC, as well as any information pertinent to the event. Relationships among different incident management stake- holders are vital to the success of FSPs as a traffic incident management tool. The most effective

84 Strategies for Work Zone Transportation Management Plans programs involve close relationships between law enforcement and FSP personnel, who trust and depend on each other. When implementing contracts for towing services, a DOT needs to consider the level of service required of the contractor and the ensuing liability involved. The services permitted may differ from region to region, depending on laws and regulations in a given state. Some programs will not allow a private contractor to move vehicles from the roadway. Others, such as PennDOT, allow the contractor to remove disabled vehicles or minor incidents from travel lanes, but also require the contractor to carry additional liability insurance to cover any claims. Allowing the contractor some indemnification has proved beneficial in allowing contracted FSPs to clear incidents from travel lanes. For example, the State of Florida allows the Florida Road Rangers some exceptions to liabilities, as the Rangers are private contractors acting as an agent of the state while moving incidents, disabled vehicles, or debris from travel lanes. Florida passed legislation, Statute 316.061(3), identifying the contracted FSP operator as an “authorized agent of the department.” This allows patrollers to remove damaged or disabled vehicles from the roadway without being considered at fault for any additional damage that occurs to the disabled vehicle. With this additional protection in place, the contract service patrol providers are less hesitant to remove obstructions from the travel lanes, and they are able to operate as an agency-operated patrol would. Training is paramount for the patrollers and may require National Incident Management training. Other factors to consider when implementing tow/freeway service patrols include the following: • Hours of operation. • Patrol route selection based on historical incident statistics. • Available personnel. • Number of vehicles. • Requirements for the types of vehicles to deploy. • Equipment needed on the vehicles. • Tools and equipment needed to perform the FSP support functions safely and effectively. 4.4.7 Design Features and Requirements Towing patrols for work zones are mostly contracted services to remove disabled vehicles from the roadway and maintain operational safety. Contracted service patrols provide specific services, as identified in their contract scope of work, for a specific number of years and with requirements for route coverage. Their contracts may also include numbers of staff and vehicles. The contracted services option can be beneficial if implemented correctly and a clear, well-written contract and scope of services have been developed and executed (e.g., decreased maximum response time following reports of an incident, improved incident-clearance time requirements). Depending on jurisdiction, tow/freeway service patrol activities range from providing basic support for stalled motorists to assisting in removing vehicles involved in major incidents to incident-coordination activities. The types of services offered include the following: • Moving disabled vehicles from work zones. • Providing fuel. • Providing water to persons being assisted or for overheated vehicles. • Changing flat tires. • Providing mechanical assistance such as jump starts, minor mechanical repairs, and tire inflation.

Traffic Incident Management and Enforcement Strategies 85 • Assisting stranded motorists with cell phone service or providing a safe place they can wait if their vehicle is disabled. • Arranging for towing by calling on behalf of the motorist. • Acting as the agency’s representative in the incident-command structure. • Requesting emergency services. • Providing information and updates to the TMC. • Assisting other responding agencies such as law enforcement, fire and rescue, emergency medical services, and other response agencies, as needed. 4.4.8 State of the Practice The following provides examples of FSP exclusively used on construction projects. 4.4.8.1 Oklahoma GO-DOT Program At the time this guidebook was written, OKDOT is pilot testing a new program focused on keeping highway work zones clear of stranded or wrecked vehicles to prevent traffic delays. The pilot program, called GO-DOT, relied on the services of two specially equipped 2017 Ford F-450 4×4 crew cab medium-duty highway rescue trucks. This program is designed to quickly move stranded vehicles out of the busy work zone to the nearest safe location and was made possible by the FHWA as part of the nearly $88 million federally funded I-235 construction contract between I-44 and North 36th Street in Oklahoma City. The two 2017 Ford F-450 trucks cost more than $400,000 to purchase and outfit. The vehicles are equipped with a wheel lift capable of lifting 3,500 lbs. and towing vehicles up to 7,800 lbs., such as recreation vehicles and travel trailers, as well as a wheel dolly for removing four-wheel- drive vehicles without damaging drivetrain components. The vehicle cabs can seat up to four additional passengers, which enables the crew to help quickly move motorists to a safer location. GO-DOT will also be equipped to provide basic auto maintenance such as jumping a dead battery, fixing a flat tire, or providing a few gallons of fuel for those who ran out of gasoline inside the work zone. The trucks are operated by the prime contractor for the I-235 construction project. When the project is completed in 2019, OKDOT will take possession of the two vehicles and hire its own operators. 4.4.8.2 WisDOT Freeway Service Teams WisDOT, state patrol, and county sheriffs implemented the Freeway Service Team (FST) program to expedite relocation of disabled and crashed vehicles by FST vehicles, which continu- ously patrol designated segments of Interstate and state highways during designated hours and through designated work zones. FSTs are frequently used as part of a project’s work zone mitiga- tion strategy to accomplish the following: • Maintain capacity in work zones and high-volume freeway segments. • Provide assistance free of charge to disabled motorists. • Minimize work zone delay. • Provide scene safety. • Provide traffic control. • Remove debris. Project design staff work with regional traffic operations to identify and quantify the need for FSTs for work zone mitigation. The FST expense is paid from the project mitigation budget.

86 Strategies for Work Zone Transportation Management Plans E-mail requests to the FST program manager for work zone FST are to be made by December 15 of the year before construction. All FST contracts are bid together in a statewide request for bids. • December 15: FST requests due for next construction year. • February: Request for bids issued. • March: Bid selections made for construction season. The FST is responsible for clearing the highway of automobiles, motorcycles, small trucks, (vehicles with a gross vehicle weight of 8,000 lbs. or less), and small nonhazardous debris. The FST relocates all cleared vehicles to the nearest drop-off location designated by the contract administrator. When responding to incident scenes, the FST provides assistance with traffic control as directed by law enforcement. 4.4.8.3 Missouri I-64 Traffic Response Program The I-64 Traffic Response program operated while I-64 was closed for reconstruction between 2007 and 2009. The I-64 project involved reconstruction of 10 mi of roadway and 30 bridges along the corridor under a full road closure. An arterial service patrol was deployed to help reduce potential mobility effects along adjacent arterial corridors based on anticipated traffic diversions from the I-64 construction project. The I-64 Traffic Response Program included six pickup trucks available on weekdays from 5:00 a.m. to 9:30 p.m. and on weekends from 8:00 a.m. to 6:30 p.m. Other examples of FSPs include • Florida Department of Transportation (FDOT) Road Rangers Service Patrol (https://www. fdot.gov/traffic/roadrangers/about.htm) • Georgia Department of Transportation (GDOT) Highway Emergency Response Operators (HEROs, http://www.dot.ga.gov/DS/Travel/HEROs) • MDSHA Coordinated Highway Action Response Team (CHART, https://chart.maryland. gov/about/incident_management.asp) • Houston TranStar Motorist Assistance Program (MAP, https://www.houstontranstar.org/ about_transtar/callmap.aspx) 4.4.9 Cost Costs depend on the number of trucks and operators available, hours of operation, roadway coverage area, and project duration. Cost estimates from available examples indicate a range between $250,000 to more than $500,000 for service on the main line only. The cost for the I-64 Traffic Response Program that included the affected arterial routes was estimated at $730,000 per year (Ryan et al. 2010). 4.4.10 Resources and References Balke, K. Traffic Incident Management in Construction and Maintenance Work Zones, FHWA-HOP-08-056, FHWA, U.S. DOT, January 2009. CDOT. Guidelines for Developing Traffic Incident Management Plans for Work Zones, Colorado Department of Transportation, 2008. FEMA. U.S. Fire Administration Traffic Incident Management Systems, FA-30, April 2008. Marquess, A., P. Desai, G. Havinoviski, and C. Heise. Safety Service Patrol Priorities and Best Practices, FHWA-HOP-16-047, FHWA, U.S. DOT, April 2017. Ryan, T., V. Chilukuri, M. Trueblood, and C. Sun. Evaluation of Freeway Motorist Assist Program, FHWA MO-2009-004, FHWA and Missouri Department of Transportation, February 2010.

Traffic Incident Management and Enforcement Strategies 87 4.5 Traffic Screens (a.k.a. Glare Screens, a.k.a. Gawk Screens) 4.5.1 Description Traffic screens, also known as glare screens and gawk screens, are screens or paddles attached to the top or back of some types of barriers to reduce headlight glare from opposing traffic. Traffic screens come in several forms and types of material. There are three general categories of screen types: • Type I. Continuous screen that is essentially opaque to light from all angles. • Type II. Continuous screen of an open material that is opaque where the angles are between 0 and 20 degrees from the driver’s eye and increasingly transparent beyond 20 degrees. • Type III. Individual elements positioned to block light at angles from 0 degrees to 20 degrees. Beyond 20 degrees visibility is clear between the elements. Traffic screens are also used in work zones to block road users’ view of construction activities that can be distracting. In this context, traffic screens are referred to as “gawk screens.” This section deals with the use of temporary work zone gawk screens. 4.5.2 When to Use The following discusses various agencies’ warrants for using traffic screens. The Arizona DOT (ADOT) Standard Specifications for Road and Bridge Construction (2008) states glare screens should be placed in urban construction zones where barriers are being used to separate opposing lanes of traffic, and when a barrier is separating traffic from areas of construction work longer than 1,500 ft. The IDOT Bureau of Design and Environment Manual (2016) provides the following list of applications for glare screen use: • Travel lane is within 2 ft of the barrier. • High amount of peripheral ambient light exists. • High volume of truck traffic exists. • Vertical or horizontal alignment of the roadway may create a headlight glare problem. IDOT encourages using glare screens if the following conditions are present: • Design speed is greater than 50 mph on an undivided and unlighted highway with median widths less than 30 ft. • Highway segment is on a divided highway that contains horizontal curves. • Nighttime crashes are unusually frequent. • Unusual transition points produce critical glare angles between traffic traveling in opposite directions. Based on a synthesis of national practices, Johnson (2017) developed three conditions for glare screen use. Meeting one or more of the conditions should lead to an engineering review of the suspected glare issue, with the intent to determine if glare screens are the appropriate glare mitigation measure for the location. When more than one of the three conditions are met, this provides additional justification for the use of glare screens. 1. Headlight glare is known to be an issue on the segment of roadway to be reviewed, based on experience or data available to agency staff. 2. Crash history attributed to glare, or with headlight glare being a contributing factor in the crash reporting, is higher than average compared with similar highway segments.

88 Strategies for Work Zone Transportation Management Plans 3. Three or more of the following characteristics are met: – Median widths less than 20 ft. – ADT volumes exceed 20,000. – Larger-than-usual percentage of heavy vehicles present. – Absence of highway lighting. 4.5.3 Benefits The use of traffic screens provides the following benefits: • Reduces distractions to drivers caused by work activities in a work zone. • Improves work zone safety by shielding drivers from oncoming headlight glare. • May improve traffic flow by reducing the distraction of watching work zone activities. • Protects vehicles from any flying debris from the work zone. 4.5.4 Expected Effectiveness No studies were found that evaluated the safety or mobility effectiveness of traffic screens in work zones. 4.5.5 Crash Modification Factor No CMF is applicable for this strategy. 4.5.6 Implementation Considerations Factors to consider when determining whether to specify use of a screening system include the following: • Night traffic volumes. • Prevalence of night highway crashes. • Highway geometry (lane/median width, vertical/horizontal curvature, etc.). • Proximity of workers to live traffic. • Extent of work area distractions. • Direction and intensity of roadway lighting and ambient light from adjoining properties. 4.5.7 Design Features and Requirements The design requirements for traffic screens are as follows: • Minimum 24-in. height. • Same length as the concrete barrier on which it will be mounted, without splicing, except accounting for longitudinal overhang between adjacent concrete barriers. • Mounted with two poles, attached to the mounting plate with the mounting plate drilled into the top of the concrete barrier. • Secured with a chain and pin, or other approved method, to the mounting pole. • Capable of being securely connected to the adjacent screen section by polyethylene brackets, or similar approved fasteners made of nonmetallic materials. • Capable of expanding without buckling. • Capable of contracting without creating gaps in the screening and while remaining securely fastened to the adjacent screen. • Faces on both sides of the screen are finished. • Capable of remaining in place from traffic gusts, wind gusts, and other outdoor elements that may move or displace the screen.

Traffic Incident Management and Enforcement Strategies 89 4.5.8 State of the Practice In March 2018, WisDOT piloted the use of gawk screens along a ½-mi stretch of the I-41 work zone in Winnebago County (Figure 4.8). The Oregon DOT Traffic Control Plans Design Manual (2014) allows the use of work zone barrier screening systems and sets out specifications for the screens: 2.5-ft tall, opaque, and purposefully designed as a gawk screen. Designs may include chain link fencing material (or equivalent roll-type material) and steel vertical posts for support. Fencing material would either be opaque, or vinyl slats could be inserted into the chain link material to provide the desired visual screening benefit. 4.5.9 Cost The cost for the I-41 project in Winnebago County, Wisconsin, was $12 per linear ft ($8 for material and $4 for installation). 4.5.10 Resources and References ADOT. Standard Specifications for Road and Bridge Construction, Arizona Department of Transportation, 2008. Bremer, W., D. A. Noyce, J W. Shaw, M. V. Chitturi, and A Bill. Guidelines for Work Zone Designers—Positive Protection, DTHF6114H00011, FHWA, U.S. DOT, May 2019. IDOT. Work Zone Traffic Control, in Bureau of Design and Environment Manual, chapter 55, Illinois Department of Transportation, June 2016. Johnson, D. A Synthesis of US Glare Screen Warrants and Design Requirements with Model Warrants and Design Guide. Master’s Thesis, University of Illinois at Chicago, 2017. Oregon DOT. Traffic Control Plans Design Manual, 9th edition, Oregon Department of Transportation, 2014. 4.6 Automated Speed Enforcement 4.6.1 Description Automated speed enforcement (ASE) involves using roadside technologies, either fixed or portable, that combine radar and image-capturing capabilities to detect speeding vehicles and collect digital photographic evidence of the speeding incident. The system captures photos of the rear of the vehicle and the license plate, embedded with the date, time, location, and recorded Without Gawk Screens With Gawk Screens Figure 4.8. Gawk screens (Credit: WisDOT).

90 Strategies for Work Zone Transportation Management Plans speed. The agency or entity authorized to issue speeding citations then reviews the images and mails a citation to the vehicle’s registered owner. ASE systems in work zones function similarly to the permanent speed camera installations used in many jurisdictions to enforce speed limits or red-light violations through automatic citations. 4.6.2 When to Use ASE systems should be considered in the following circumstances: • There is an active work zone on an expressway or controlled-access highway (speed limit of 45 mph or higher). • Workers are exposed or there are motorist hazards (lane shifts, lane splits, reduced lane widths, closed shoulders, rough pavement, etc.). • Work zone will remain active over a long period of time. • 24-hour speed enforcement is desired. • Law enforcement availability is limited. 4.6.3 Benefits The use of ASE systems in work zones provides the following benefits: • Increases work zone speed limit compliance, thereby reducing the potential for crashes. • Improves worker safety. • Allows law enforcement officers to focus on other job duties (when an officer is not required to cite a speeding vehicle, as is allowed in Maryland and Pennsylvania). • Eliminates officers’ exposure to hazardous roadside traffic stops. 4.6.4 Expected Effectiveness ASE systems have significantly reduced the number of drivers exceeding the PSL, the number of crashes in work zones, and the number of injuries and fatalities related to work zone crashes. • The number of vehicles traveling 12 mph or more above the work zone speed limit has been shown to decrease by 85 percent (MDSHA 2019). • Free-flow speed has been found to decrease by 6.8 mph (Avrenli, Benekohal, and Ramezani 2012). • Automobile average speeds have been shown to decrease by 5.1–8.0 mph in the median lane and 4.3–7.7 mph in the shoulder lane (Benekohal et al. 2010). • Truck average speeds have been found to decrease by 3.7–5.7 mph in the median lane and 3.9–6.4 mph in the shoulder lane (Benekohal et al. 2010). • The number of vehicles exceeding mean speed has been shown to decrease by an average of 23.7 percent (Oregon DOT 2010). 4.6.5 Crash Modification Factor Table 4.3 shows the CMF for ASE. Chapter 13 provides more information on developing WZCMFs. 4.6.6 Implementation Considerations To begin using ASE in work zones, a state will first need to enact legislation that allows its implementation. States that already have legislation allowing automated enforcement of speeding

Traffic Incident Management and Enforcement Strategies 91 or red-light enforcement can provide a basis for a legislative request to allow ASE in work zones. Information on existing legislation permitting, limiting, or prohibiting the use of speed or red-light cameras at the state or local level can be found on the GHSA webpage.10 Agencies typically involved include the state DOT, state police or local police, the state department of motor vehicles, and courts. Whether workers need to be present in a work zone for drivers to receive a speeding ticket depends on state legislation. Advanced signs are necessary to alert drivers of the PSL and the use of ASE in the work zone. Once agencies implement ASE for equipment and vehicles in designated work zones, officials normally operate the system during a well-publicized mandatory warning period of several weeks, during which violators receive warnings instead of citations. Currently, the Maryland SafeZones program issues warnings for 3 weeks at new long-term work zones. Citations are issued after the 3-week period. For short-term projects, such as paving projects, there is no warning period; rather, signs are posted to notify drivers that ASE will be in effect in the work zone. In summary, agencies need to consider the following factors for ASE use in work zones: • Legislation is required to authorize the use of ASE systems in work zones. • Warning signs need to be placed well before drivers arrive at the work zone to inform them that an ASE system is in use. • Systems usually need continuous staffing during deployment. • The vehicle-mounted setup should be placed behind a protected area, preferably behind a barrier or guiderail, otherwise behind a TCD or on the shoulder. • The grade of the roadway and any other features must not impair visibility of the setup. • ASE systems are not intended to replace other work zone safety operations. • Because each construction project is different, agencies can determine the selection, appli- cation, and location of ASEs on a project-by-project basis. 4.6.7 Design Features and Requirements The following are the minimum requirements for ASE systems in work zones: • Field equipment for speed detection and image capture can be mobile vehicle units (occupied or unoccupied) or temporary pole-mounted units. Each unit includes speed- measurement devices, violation-capturing systems, systems mounts, power supplies, site- deployment computers, cables, data-upload systems, and all other hardware required to operate the system as intended. 10 https://www.ghsa.org/state-laws/issues/speed%20and%20red%20light%20cameras, accessed May 12, 2020. Crash Type Crash Severity Facility Type Volume Range (AADT) CMF Standard Error All Fatal, serious and minor injury All Not specified 0.83 0.01 (unadjusted) NOTE: There were no studies available that specifically examined the safety effects of using ASE in work zones. The CMF was derived from past studies on nonwork zone roads. CMF = crash modification factor; ASE = automated speed enforcement; AADT= annual average daily traffic. Table 4.3. CMFs for ASE.

92 Strategies for Work Zone Transportation Management Plans • Speed-detection equipment includes radar, laser, or other proven technology that has International Association of Chiefs of Police approval for speed measurement. Approved speed-detection equipment needs to have an ongoing maintenance record to ensure it is calibrated and functioning properly. The speed-detection equipment should be able to immediately communicate error messages to the operator and record the date and time of system shutdown in the event of a malfunction or error. • Image-capture equipment must be able to record front and rear images of a vehicle license plate upon a signal trigger from the speed-detection equipment. The image-capture equip- ment detection should include supporting hardware and software capable of simultaneously collecting readable license plate images in various lighting and environmental conditions. Images should be captured at sufficient resolution to display plate characters and data at clearly legible quality from both reflective and nonreflective plates. • A program database stores all pertinent program information such as the notice of violation information, violation imagery, registered vehicle owner’s number of offenses, notice of viola- tion mailing date, date of and violator’s response, appeal hearing dates for violators, hearing results, and collections received or outstanding. • Work zone signs are placed well before the ASE operation, clearly indicate that ASE systems are in use, and specify the lowered speed limit, if any. • Systems for violation administration manage payment processing and customer service. 4.6.8 State of the Practice 4.6.8.1 Pennsylvania The Pennsylvania State Legislature amended Section 102 and Title 75 Pa C.S. §3369, granting permission for ASE to be used within active work zones in the commonwealth. This act, Senate Bill 172, was signed into law on October 19, 2018. Drivers exceeding the PSL by 11 mph or more in active work zones will get a warning in the mail for a first offense and will be ticketed $75 and $150 fines for second and third offenses. ASE violations are considered civil violations; therefore, no license points are assessed. ASE began in fall 2019 with full deployment planned for 2020. Pennsylvania will pilot the ASE system for 5 years. PennDOT will start with two ASE units that will be moved between projects statewide. Eventually, the department will have 10 speed cameras for the initiative. Appendix F provides the operational process flowchart for ASE deployment. 4.6.8.2 Maryland MDSHA, the Maryland Transportation Authority, and the Maryland State Police began the Maryland SafeZones in October 2009. The SafeZones pilot program ran from October 2009 through June 2010, with the long-term SafeZones program beginning on July 1, 2010 (Transportation Article § 21-810). SafeZones deploys speed cameras aboard sport-utility vehicles called mobile ASE units. These units can be located within the limits of any work zone on expressways and controlled-access highways where the speed limit is 45 mph or greater. Images are only captured and used to issue a citation if a vehicle is exceeding the posted work zone speed limit by 12 mph or more (Figure 4.9). Citations may be issued regardless of whether workers are present in the work zone. Violators must pay a $40 fine and no license points are assessed. Maryland has seven mobile ASE units that rotate through a series of predetermined work zones throughout the state. SafeZones program stakeholders use a variety of factors to deter- mine camera deployment locations, including roadway and work zone characteristics (such as facility type), speed limit, TTC activities, and whether traditional in-person enforcement is

Traffic Incident Management and Enforcement Strategies 93 viable. Drivers can find out which work zones are using ASE by going online to the Maryland SafeZones website (http://www.safezones.maryland.gov). Since 2010, SafeZones has been deployed at 78 enforcement locations in work zones on Inter- states, national highways, and Maryland state routes. When the program began, approximately 7 out of every 100 drivers in SafeZones were exceeding the speed limit by 12 mph or more. As of April 2019, fewer than 1 driver of every 100 is receiving a citation, showing a more than 85 percent reduction in the number of vehicles traveling 12 mph or more above the work zone speed limit (Figure 4.10). Figure 4.9. Automated speed enforcement signing (Credit: MDSHA, http://www. safezones.maryland.gov). Figure 4.10. MDSHA ASE speeding quarterly report (Credit: MDSHA, http://www.safezones. maryland.gov).

94 Strategies for Work Zone Transportation Management Plans 4.6.8.3 Illinois In 2006, Illinois was the first U.S. state to implement ASE in work zones. The legislation requires that construction workers be present when ASE is in use. It allows ASE use day or night, even if the workers are behind temporary concrete barriers. The law also requires special signs to be posted to inform motorists of ASE in the work zones (Figure 4.11). ASE began with a pilot program of two vans; as of this writing, five vans were in use during the construction season (usually April–October), with deployment limited to freeway work zones. The vans are staffed by specially trained Illinois State Police officers. Issuing a speeding citation is at the discretion of the officer and is generally limited to clear cases of excessive speed. The minimum fine was $375 for the first offense and $1,000 for the second offense; if the second offense is within 2 years of the first offense, the driver’s license is suspended for 90 days. 4.6.8.4 Oregon The 2007 Oregon legislative assembly passed House Bill 2466, allowing the Oregon DOT to use photo radar in work zones on non-Interstate state highways. To this effect, the Oregon DOT conducted a demonstration project to examine the effect of photo radar speed enforcement on traffic speed through an active highway work zone in 2010. The 2013 Oregon Legislature passed House Bill 2465 (ORS 810.441).11 This legislation replaced House Bill 2466, which expired on December 31, 2014. ORS 810.441 allows the Oregon DOT to request the Oregon State Police or other law enforce- ment jurisdictions operate photo radar in highway work zones on state highways, including Interstates. ORS 810.441 also identified criteria surrounding the use of photo radar, including the require- ment to deploy photo radar within 100 yards of workers or within 100 yards of a configuration change. Signs announcing the use of photo radar must be posted, as well as the actual speed of Figure 4.11. Illinois ASE van with radar speed display sign (Credit: IDOT). 11 https://www.oregonlegislature.gov/citizen_engagement/Reports/ODOTPhotoRadarWorkZonePilotReport2015.pdf, accessed May 12, 2020.

Traffic Incident Management and Enforcement Strategies 95 the vehicle, which must be displayed within 150 ft of the photo radar unit. A uniformed police officer in a marked vehicle must be present for a citation to be issued. In 2018, the Oregon DOT requested the City of Medford Police Department to provide work zone photo radar on the I-5 Medford Viaduct and Barnett Road Overpass project. Medford Police Department deployed the work zone photo radar van for 15 days. Each deployment lasted for 4 hours. The legal speed through the work zone was 40 mph. For this project, more than 1,058 work zone photo radar violations were captured and 686 speeding citations issued (an average of 11.4 per hour). Speeds recorded for the violations averaged 56 mph, with a high speed of 91 mph. As of this writing, Stage 2 of the I-5 project is currently under development. This project will use work zone photo radar and perform a formal speed-comparison study. The Portland City Council, through City Ordinance #172517, directed the police bureau to deploy photo radar in highway work zones. The bureau used photo radar to enforce speed limits at two work zones during 2013 and 2014. 4.6.8.5 Washington Washington, which authorized legislation in 2007, launched a pilot program in 2008, and although the legislature extended the pilot program to June 2013, WSDOT has not redeployed ASE beyond the 2008 pilot. 4.6.9 Cost ASE costs are estimated at $150,000–$250,000, including system hardware and software costs. 4.6.10 Resources and References Avrenli, K. A., R. F. Benekohal, and H. Ramezani. Four-Regime Speed-Flow Relationships for Work Zones with Police Patrol and Automated Speed Enforcement, University of Illinois, Urbana, 2012. Benekohal, R. F., A. Hajbabaie, J. C. Medina, M.-H. Wang, and M. Chitturi. Speed Photo-Radar Enforcement Evaluation in Illinois Work Zones, FHWA-ICT-10-064, January 2010. Boyer, R. Highway Worker Safety: Automated Speed Enforcement, Caltrans Division of Research and Innovation, August 3, 2011. Cameras in Work Zones: Final Report, Pennsylvania State Transportation Advisory Committee, November 2012. Chan, C.-Y., K. Li, and J.-H. Lee. Assessing Automated Speed Enforcement in California. California PATH Research Report UCB-ITS-PRR-2010-2, April 2010. Chan, C.-Y. Field Evaluation of Work-Zone Automated Speed Enforcement Equipment and Traffic Monitoring Devices. Presented at 88th Annual Meeting of the Transportation Research Board, Washington, D.C., 2009. Douma, F., L. Munnich, J. Loveland, and T. Garry. Identifying Issues Related to Deployment of Automated Speed Enforcement, CTS Project #2012045, Center for Transportation Studies, University of Minnesota, July 2012. Franz, M. L., and G.-L. Chang. Effects of Automated Speed Enforcement in Maryland Work Zones, University of Maryland, 2010. General Assembly of Pennsylvania, Senate Bill 172. 2017. (https://www.legis.state.pa.us/cfdocs/legis/PN/Public/ btCheck.cfm?txtType=PDF&sessYr=2017&sessInd=0&billBody=S&billTyp=B&billNbr=0172&pn=2024, accessed on April 9, 2019). Maryland State Highway Administration (MDSHA). Automated Speed Enforcement in Work Zones (http:// www.safezones.maryland.gov, accessed April 9, 2019). Oregon DOT. Photo Radar Speed Enforcement in a State Highway Work Zone: Yeon Avenue Demonstration Project, Oregon Department of Transportation, OR-RD-10-17, April 2010. WSDOT. Automated Enforcement in Work Zone Pilot Project, Fall 2008/Spring 2009 Deployment. https://safety. fhwa.dot.gov/speedmgt/ref_mats/fhwasa1304/resources2/31%20-%20Automated%20Enforcement%20 in%20Work%20Zone%20Pilot%20Project.pdf, accessed April 9, 2019.

96 Strategies for Work Zone Transportation Management Plans 4.7 Police Enforcement 4.7.1 Description Police enforcement involves police patrols in the work zone under a contractual arrangement with the agency or contractor. Law enforcement activities can be in the form of stationary patrol vehicles, a police traffic controller (an officer does the flagging), circulating patrol vehicles, stationary patrol vehicles with their lights on, and stationary patrol vehicles with radar on. 4.7.2 When to Use Federal regulations (23 CFR 630, Subpart K) list conditions for which work zone enforcement may be a valuable addition to the standard traffic controls. These include the following: • Frequent worker presence adjacent to high-speed traffic without positive protection devices. • Traffic control setup or removal that presents significant risks to workers and road users. • Complex or very short term changes in traffic patterns with significant potential for road-user confusion or worker risk from traffic exposure. • Night work operations that create substantial traffic safety risks for workers and road users. • Existing traffic conditions and crash histories that indicate a potential for substantial safety and congestion effects related to the work zone activity, which may be mitigated by improved driver behavior and awareness of the work zone. • Work zone operations that require brief stoppage of all traffic in one or both directions. • High-speed roadways where unexpected or sudden traffic queuing is anticipated, especially if the queue forms a considerable distance in advance of the work zone or immediately adjacent to the work space. • Other worksite conditions in which traffic presents a high risk for workers and road users, such that the risk may be reduced by improving road-user behavior and awareness. 4.7.3 Benefits The use of police services in work zones provides the following benefits: • Speed control. Extensive research has shown that the presence of a marked police vehicle is simply the most effective speed-control measure in work zones. • Enforcement. Police enforcement increases motorists’ compliance with work zone regula- tions and discourages aggressive or careless driving. • Traffic incident and accident management. Work zone officers can immediately respond to any incident or accident, thus quickly restoring traffic flow and enhancing the safe operation of the work zone. • Traffic control. A police officer commands respect and authority. Thus, the officer’s presence facilitates the safe and efficient movement of traffic through the work zone (e.g., traffic merging during lane closure). • Increased visibility. The presence of a marked police vehicle in the work zone is an effective measure to capture the attention of passing motorists, raising their alertness. 4.7.4 Expected Effectiveness The use of police enforcement for work zone activities has been studied extensively with the following results: • 16 percent to 24 percent reduction in speeding (Gan et al. 2018). • 1.7–6.5 mph reduction in work zone mean speeds; 5.5 percent to 16 percent reduction in percentage of traffic exceeding work zone speed limit (Lee, Azaria, and Neely 2014).

Traffic Incident Management and Enforcement Strategies 97 • Speed reduction of 3.6 mph for automobiles and 2.7 mph for trucks (Chen and Tarko 2013). • 6.3 mph reduction in free-flow speed (Avrenli, Benekohal, and Ramezani 2012). • 4–12 mph reduction in average speeds for stationary patrol vehicles and 2–3 mph for circu- lating patrol vehicles (Carpenter, Hammond, and Lenzi 2012). • 5–7 mph reduction in mean speeds (Benekohal et al. 2010; Hajbabaie et al. 2011). • 1.4 mph reduction in average daytime speed, 1.1 mph reduction in average nighttime speed, and 17 percent reduction in percentage of vehicles exceeding PSL (Chen et al. 2007). • 6 mph reduction in average vehicle speeds (Bowie 2003). • 17 percent reductions in mean speeds; 15 percent reduction in 85th percentile speeds (Lindly, Noorjahan, and Hill 2002). • 8–11 mph reduction in 85th percentile speeds (MnDOT 1999). 4.7.5 Crash Modification Factor Table 4.4 shows the CMF for police enforcement. Chapter 13 provides more information on developing work zone CMFs. 4.7.6 Implementation Considerations Obtaining sufficient police resources for work zone enforcement remains an ongoing concern in many states and is a limiting factor for many types of work zone enforcement. This issue has many dimensions, including budget and finance, human resources and labor relations, and organizational and jurisdictional factors. To a large extent, each agency’s situation is a unique reflection of its state laws, collective bargaining agreements, and the established degree of cooperation or competition between state, county, and local law enforcement agencies. 4.7.7 Design Features and Requirements Generally, using law enforcement officials on a continuing basis is warranted only on freeways or Interstate roadways where traffic volumes are in excess of 25,000–30,000 annual average daily traffic (AADT) and lanes are closed in peak periods. Where lane closures are limited to off-peak periods, a higher AADT (approximately 35,000) is typically considered a minimum threshold volume to justify law enforcement. Also, to be effective, the construction work must allow space for law enforcement officials to stop violators at the point of infraction. If sufficient shoulder area does not exist, the city should consider constructing temporary pull-off areas. These guidelines are intended for long- term contractual law enforcement activities. They are not intended to limit the short-term use of law enforcement agencies for construction control for lane closures, traffic lane switching, and the like. Table 4.4. CMFs for police enforcement. Crash Type Crash Severity Facility Type Volume Range (AADT) CMF Standard Error All All Not specified 696 to 124,907 0.585 Not calculated NOTE: The CMF was obtained using data from Indiana work zones and a random-effect negative binomial crash-frequency model, in which each observation represented 1 month of data. Detailed hourly data with enforcement efforts were not available at enough sites to be used in the model. CMF = crash modification factor; AADT = annual average daily traffic.

98 Strategies for Work Zone Transportation Management Plans 4.7.8 State of the Practice Most states have policies regarding the use of uniformed off-duty police officers in high- way construction work zones. Most frequently, the state DOT funds the program for the law enforcement agency. Police enforcement programs are often administered through an inter- agency agreement or memorandum of understanding between the state highway agency and the state police or state highway patrol. Arrangements vary widely, however. In some cases, an unwritten policy of interagency cooperation allows the law enforcement agency to provide on-duty uniformed officers as needed. Some highway agencies work with local police agencies in addition to the state police. 4.7.9 Cost Estimates of the cost of police enforcement range from $150–$250 per officer per hour. 4.7.10 Resources and References Avrenli, K. A., R. F. Benekohal, and H. Ramezani. Four-Regime Speed-Flow Relationships for Work Zones with Police Patrol and Automated Speed Enforcement, University of Illinois, Urbana, 2012. Arnold, E. D. Use of Police in Work Zones on Highways in Virginia, VTRC 04-R9 Virginia Transportation Research Council, Virginia Department of Transportation and the University of Virginia, Charlottesville, 2003. Benekohal, R. F., P. T. V. Resende, and R. L. Orloski. Effects of Police Presence on Speed in a Highway Work Zone: Circulating Marked Police Car Experiment. Report FHWA-IL/UI-240. University of Illinois, Urbana, 1992. Benekohal, R. F., A. Hajbabaie, J. C. Medina, M.-H. Wang, and M. Chitturi. Speed Photo-Radar Enforcement Evaluation in Illinois Work Zones. FHWA-ICT-10-064. January 2010. Bowie, J. M. Efficacy of Speed Monitoring Displays in Increasing Speed Limit Compliance in Highway Work Zones. Brigham Young University. Theses and Dissertations. Paper 87, 2003. Carpenter, J., P. Hammond, and J. C. Lenzi. Law Enforcement in Work Zones: Survey Results, State’s Approaches and Lessons Learned. AASHTO Subcommittee on Construction Annual Meeting, San Francisco, CA, August 16, 2012. Chen, E., and A. Tarko. Best Practices for INDOT-Funded Work Zone Police Patrols. Center for Road Safety, School of Civil Engineering, Purdue University, West Lafayette, IN, 2012. Chen, E., and A. Tarko. Programming Police Enforcement in Highway Work Zones, Center for Road Safety, School of Civil Engineering, Purdue University, West Lafayette, IN., 2013. Chen, Y., X. Qin, and D. A. Noyce. Evaluation of Strategies to Manage Speed in Highway Work Zones. Presented at 86th Annual Meeting of the Transportation Research Board, Washington, D.C., 2007. Gan, A., W. Wu, W. Orabi, and P. Alluri. Effectiveness of Stationary Police Vehicles with Blue Lights in Freeway Work Zones, Florida International University, Miami, May 2018. Guidelines on Use of Law Enforcement in Work Zones, FHWA, U.S. DOT, Washington, D.C., 2011. Hajbabaie, A., J. C. Medina, M. H. Wang, R. F. Benekohal, and M. Chitturi. Sustained and Halo Effects of Various Speed Reduction Treatments in Highway Work Zones. Transportation Research Record: Journal of the Transportation Research Board, No. 2265, 2011, pp. 118–128. Lee, B. H. Y., D. Azaria, and S. Neely. Work Zones and Travel Speeds: The Effects of Uniform Traffic Officers & Other Speed Management Measures, UVM Transportation Research Center, University of Vermont–Burlington, 2014. Lindly, J., S. Noorjahan, and S. Hill. Identification of Potential Enhancements for Work Zone Safety. Alabama Department of Transportation. April 2002. University Transportation Center for Alabama, University of Alabama, University of Alabama in Birmingham, and University of Alabama at Huntsville, 2002. McCoy, P.T., and Bonneson, J.A. Work Zone Safety Device Evaluation. Report SD-92-10F. Center for Infrastruc- ture Research, Lincoln, Neb., 1993. MnDOT. Effectiveness of Law Enforcement in Reducing Vehicle Speeds in Work Zones, Office of Construction, Construction Programs Section, January 1999. Ravani, B., C. Wang, W. A. White, and P. Fyhrie. Evaluation of Methods to Reduce Speed in Work Zones, AHMCT Research Center, University of California–Davis, 2012. Richards, S. H., R. C. Wunderlich, and C. L. Dudek. Field Evaluation of Work Zone Speed Control Techniques. Transportation Research Record: Journal of the Transportation Research Board, No. 1035, 1985, pp. 66–78.

Traffic Incident Management and Enforcement Strategies 99 Srinivasan, S. Analyzing Effectiveness of Enhanced Penalty Zones and Police Enforcement as Freeway Speed-Control Measures, Southeast Transportation Center, University of Tennessee, Knoxville, 2011. Sulbaran, T., and D. Marchman. Effectiveness of Increased Law Enforcement Surveillance on Work Zone Safety in Mississippi, University of Southern Mississippi, Hattiesburg, 2007. Ullman, G. L., and S. D. Schrock. Feasibility and Design of Enforcement Pullout Areas for Work Zones, Report No. FHWA/TX-02/2137-2, Texas A&M Transportation Institute, College Station, 2003. Ullman, G. L., M. A. Brewer, J. E. Bryden, M. O. Corkran, C. W. Hubbs, A. K. Chandra, and K. L. Jeannotte. “NCHRP Project 3-80: Traffic Enforcement Strategies in Work Zones—Final Report.” 2010. Ullman, G. L., M. A. Brewer, J. E. Bryden, M. O. Corkran, C. W. Hubbs, A. K. Chandra, and K. Jeannotte. NCHRP Report 746: Traffic Enforcement Strategies for Work Zones. Transportation Research Board of the National Academies, Washington, D.C., 2013.

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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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