Use of Smart Work Zone Technologies for Improving Work Zone Safety (2022)

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Introduction 7   Source: Massachusetts DOT 2016a. Figure 1. Example layout for traveler information system for travel time and delay. Components of Smart Work Zone Technologies As shown in Figure 9, smart work zone systems generally include the following components (Massachusetts DOT 2016a): • Detection and surveillance equipment, such as traffic sensors and video cameras, gather data in the vicinity of the work zone and transmit the data to the central processing system. • Central processing systems are used for data storage and analysis and for transmitting messages to various dissemination outlets. • Dissemination outlets, such as 511 systems, changeable message signs (CMSs), smart phone applications, and websites, provide real-time information regarding travel conditions in work zones to the general public. • Ancillary systems supply power to smart work zone equipment and facilitate communication between system components.

8 Use of Smart Work Zone Technologies for Improving Work Zone Safety Source: IBI Group 2017. Figure 2. Example layout for queue warning system (VMS = variable message sign).

Introduction 9   Source: New Hampshire DOT 2011. Figure 3. Example layout for dynamic late-merge system.

10 Use of Smart Work Zone Technologies for Improving Work Zone Safety Source: New Hampshire DOT 2011. Figure 4. Example layout for dynamic speed limit system, also known as variable speed limit systems (TC = traffic control).

Source: Stephens et al. 2019. Source: Athey Creek Consultants 2018. Figure 5. Types of work zone activity data (WZAD) for internal agency stakeholders and external stakeholders (WZ = work zone). Figure 6. Example flowchart for implementation of smart arrow board system for Minnesota DOT (IRIS = Intelligent Roadway Information System; RTMC = Regional Traffic Management Center).

Source: IBI Group 2017. Figure 7. Typical layout for work zone intrusion alarm system.

Introduction 13   Source: IBI Group 2017. Figure 8. Typical layout for entering/exiting vehicle notification system.

14 Use of Smart Work Zone Technologies for Improving Work Zone Safety Source: Massachusetts DOT 2016a. Figure 9. Typical components for smart work zone technologies. Synthesis Methodology e synthesis approach included a literature review, survey, and case examples. e existing literature from many dierent sources, including guides, research studies, and DOT policies, standards, and specications, was reviewed and synthesized. An online survey was distributed to the DOTs for all 50 states and the District of Columbia. Responses were received from all 51 DOTs, leading to a 100% response rate. Follow-up interviews were conducted with repre- sentatives from seven DOTs to develop case examples of DOT’s experiences with smart work zone technologies. Synthesis Organization e chapters of this synthesis are organized as follows: • Chapter 2 describes the comprehensive literature review of research, guidance, policies, stan- dards, and specications. • Chapter 3 provides information on state DOT practices based on the survey results. • Chapter 4 contains case examples for seven state DOTs. • Chapter 5 presents a summary of synthesis ndings and recommendations for future research. • e References section provides a list of sources used for this report, and the List of Abbrevia- tions provides denitions for the abbreviations and acronyms found in the report. • Appendices (Table 1) provide supplemental information for the synthesis.

Introduction 15   Appendix Title A Survey Questionnaire B List of Responding DOTs C Individual Survey Responses from DOTs D Suitability of Smart Work Zone Technologies Based on Project Characteristics E Summary of Existing Literature, Guidance, and Standards for Smart Work Zone Technologies F Examples of FHWA and DOT Tools for Assessing Smart Work Zone Technologies During the Planning Phase G Survey Results for DOT Use of Smart Work Zone Technologies by Climate Region H Survey Results for DOT Performance Ratings of Smart Work Zone Technologies by Climate Region I Summary of Synthesis Findings by Smart Work Zone Technology Table 1. Appendices.

16 This chapter presents the results of the literature review for smart work zone technologies. Sources compiled for the literature review include guides, research reports, journal articles, and the policies, manuals, specifications, and standards of state DOTs. The chapter is organized into the following sections: general guidance for smart work zone technologies; evaluations, guidance, and standards for specific smart work zone technologies; and performance measures for smart work zone technologies. Tabular summaries of literature, guidance, and standards for smart work zone technologies are provided in Appendix E. General Guidance, Research Studies, and Implementation Tools for Smart Work Zone Technologies As described in the following sections, general guidance for smart work zone technologies is available from the FHWA, state DOTs, and other sources. In addition, general research studies have investigated the effectiveness of smart work zone technologies and the availability of work zone safety technology studies. FHWA Resources for Smart Work Zone Technologies Various resources to facilitate implementation of smart work zone technologies are available from the FHWA. A FHWA guide provides direction on implementing smart work zone tech- nologies and identifies the key steps for implementation (Figure 10) (Ullman et al. 2014). The guide includes a table showing the applicability of different smart work zone technologies based on project characteristics (Appendix D). In addition to the implementation guide, a companion tool is available to facilitate and document the decision-making process for smart work zone tech- nologies (GitHub 2021b). Another publication from FHWA presents four case studies from three state DOTs (Illinois, Nevada, and Utah) to demonstrate the implementation of smart work zone technologies to improve safety and mobility in work zones (Ullman and Schroeder 2014). General Research Studies for Smart Work Zone Technologies In addition to the FHWA resources, general research studies have investigated different aspects of smart work zone technologies. A framework to evaluate the effectiveness of smart work zone technologies based on five performance measures was developed by Edara et al. (2013a) (Figure 11). The application of the framework through case examples found benefit-cost ratios ranging from 2.1 to 1 to 6.9 to 1 for using smart work zone technologies. An analysis by Nnaji et al. (2020) included a review of the results of 147 work zone safety technology studies. The researchers grouped the technologies as speed reduction systems, intrusion prevention and warning systems, C H A P T E R   2 Literature Review

Literature Review 17   or human-machine-interaction detection systems and found that 68% of studies concerned speed reduction systems. State DOT Resources for Smart Work Zone Technologies State DOT resources to support the implementation of smart work zone technologies include guidelines, special provisions, typical applications, decision-making tools, scoring charts (Appendix F), and spreadsheet tools. These resources are highlighted in the following sections. DOT Guidelines, Standards, Specifications, and Typical Applications for Smart Work Zone Technologies • The Minnesota DOT has established draft special provisions for several smart work zone tech- nologies, including an end of QWS, travel time, temporary ramp metering, travel time, active zipper merge, electronic workers-present speed limit, truck or traffic entering, and excessive speed warning (Minnesota DOT 2020b, Minnesota DOT 2020c). • Long-term typical applications for various smart work zone technologies are available from the Minnesota DOT (Minnesota DOT 2021b). • A flowchart from the Minnesota DOT outlines processes for planning, deployment, integra- tion, monitoring, and troubleshooting of smart work zone technologies (Minnesota DOT n.d.). • A standard-operating-procedures document from the Massachusetts DOT presents guidance and requirements for contractors operating smart work zone technologies in Massachusetts (Massachusetts DOT 2016a). The document provides information regarding the design, deploy- ment, operation, and maintenance of the smart work zone. • The Massachusetts DOT also provides standards for designing smart work zone applica- tions, including a seven-step process for any smart work zone deployment and information concerning the capabilities, components, and layouts of various systems (Massachusetts DOT 2016a). • The Wisconsin DOT includes guidance on the placement of smart work zone equipment in its ITS Design & Operations Guide (Wisconsin DOT 2009). Information provided encompasses Source: Ullman et al. 2014. Source: Edara et al. 2013a. Figure 10. Implementation process for smart work zone technologies. Figure 11. Framework for the evaluation of smart work zone technologies.