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4 1.0 Introduction Periodic work zones are necessary to build, maintain, rehabilitate, enhance, and reconstruct this nationâs roadway network. Over the course of one year, it was estimated that 26.5% of the National Highway System (NHS) has at least one day with a work zone in place. In the peak summer months, it is estimated that 7.9% of the NHS has a work zone in place on any given workday (1). 1.1. Work Zonesâ Effect on Safety Unfortunately, work zones can mean daily changes in traffic patterns, narrowed rights-of-way (ROW), and other construction activities that create a combination of factors resulting in crashes. According to the National Work Zone Safety Information Clearinghouse, from 2010 through 2018, an average of 679 people died each year as a result of crashes in work zones.. Table 1 shows the work zone fatality and injury data for the years 2013â2017 (2). Table 1. Work zone crash factsâfatalities and injuries. Year Total Work Zone Fatalities Total Work Zone Injuries Total Work Zone Crashes 2010 586 36,000 87,000 2011 590 39,000 91,000 2012 619 30,000 76,000 2013 593 25,000 68,000 2014 670 31,000 89,000 2015 718 35,000 97,000 2016 782 61,000a 158,000a 2017 809 37,000a 94,000a 2018 755 NA NA Average 680 36,750 95,000 NOTE: aNHTSA has redesigned the sampling process used to compute these estimates. Therefore, 2016 and later data are not directly comparable to data from 2015 and before. Data for injuries and crashes greater than 500 have been rounded to the nearest 1,000 and values less than 500 have been rounded to the nearest 100 to reflect the level of uncertainty associated with these estimates. NA = not available. Additionally, work zone crashes occur in a constrained driving environment, cause congestion and excessive delays. Estimates are that work zones crashes account for 10% of overall congestion and 24% of nonrecurring freeway delays nationwide (4). Reducing these crashes and delaysâand their negative effects on lives and the economyâ requires a better understanding of the effectiveness of work zone transportation management
5 strategies. Transportation management plans are a set of coordinated strategies designed to help agencies achieve their work zone projects goals related to traffic mobility, efficient system operation, motorists and workers safety, and other operational targets. State DOTs and other transportation agencies currently develop and implement TMPs, which typically involve coordinated strategies related to TTC, TO, and public information. TMPs also help road users traverse work zones safely by understanding project effects, alternatives, scheduling, and anticipated benefits. State DOT practices, however, vary considerably with respect to what the agency considers when selecting strategies to integrate into a TMP. Practitioners can be uncertain of the effectiveness of their safety solutions and the value of their economic benefit. As a result, transportation agencies may not understand the application, its effectiveness, or the cost- efficiency of their TMP decisions. 1.2. Project Objective The objectives of this project, NCHRP 03-111: Effectiveness of Work Zone Transportation Management Plan Strategies, are to: â¢ Provide information on a wide range of strategies for work zone practitioners in the form of a âGuidebook.â â¢ Conduct field evaluations of three selected TMP strategies: truck lane restrictions, ramp metering, and reversible lanes. 1.3. Report Purpose This report focuses on the field evaluation of the following three strategies - truck lane restrictions, ramp metering, and reversible lanes. The guidebook is published as NCHRP Research Report 945 and is available on the TRB website. The guidebook provides a compendium of current knowledge on work zone strategies, including suggestions on when to use each and its benefits, effectiveness, related technical issues, design requirements, state of the practice, and cost. 1.4. Report Organization This report contains nine chapters. Following this Introduction, Chapter 2 provides an overview of the guidebook, which, as noted, is provided separately as a standalone document. Chapter 3 presents the results of a practitioner survey intended to solicit information and perspectives from state DOTs on how they manage a variety of work zone challenges.
6 Chapter 4 presents the methodology for selecting strategies for field evaluation and the final list of treatments for field evaluation. Appendix A provides the survey tool used to solicit state DOT input. Chapter 5, 6, and 7 presents field evaluation results of three strategies: truck lane restrictions, ramp metering, and reversible lanes. Chapter 8 provides a summary of findings relating to the three field evaluations.