Alternative Technologies for Mitigating the Risk of Injuries and Deaths in Work Zones: Conduct of Research (2022)

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5 CHAPTER 1: Background Roadway construction and maintenance work zones are particularly hazardous driving and work environments for commuters and workers, respectively. Examples of conditions that create safety hazards in work zones are abundant, and include when the work is performed at night, the presence of high-speed traffic adjacent the work, limited or no positive protection of the workers, impaired drivers, and extreme weather conditions. Additionally, safety hazards can arise due to the location and nature of the construction and maintenance operations, the presence of large equipment, schedule pressures, crowded work areas, lack of visibility and communication, and many other worker behaviors, work operation, and site condition impacts. Tragically, while safety practices and standards are regularly implemented, driver and worker injuries and fatalities still occur in work zones. The leading causes of death in the road and bridge construction sector are worker run- overs (a result of vehicle intrusions), back-overs, and falls (FHWA 2016). The impact of work zone crashes goes beyond the social and emotional impact of the loss of life and injured citizens and workers. The cost associated with each fatal crash can amount to millions of dollars (Blincoe et al. 2015). Additional losses to the public due to road closures, decreased mobility, and increased travel times as a result of crashes in work zones can have a further negative impact on a state’s economy (Blincoe et al. 2015). Extensive research has been conducted to learn how to improve safety in work zones. Prior research has focused on both the drivers passing through the work zone and the work operations within the work zone. With the understanding that crash severity increases with greater speed (Aarts and Schagen 2006), reducing vehicle speed within the work zone has been studied extensively. This prior research has resulted in the identification of recommended practices and controls for reducing speed in work zones including the use of law enforcement, variable message signs, temporary rumble strips, radar speed signs, and other traffic calming devices (Debnath et al. 2012). Research has also explored how to improve worker safety through work practices and technologies, such as pre-task work planning, proximity alarms, wearable lighting, and positive protection measures (Nnaji et al. 2020). However, given the continued prevalence of crashes resulting in motorist and worker injuries and fatalities in work zones, further investigation of means to improve safety are needed. Research efforts continue to explore ways to improve safety in work zones. One promising approach to improving safety that has received increased attention is the use of emerging technologies to mitigate and alert workers to the intrusion of vehicles into the work zone. Technologies such as wireless communication devices, radio frequency identification (RFID), light detection and ranging (LiDAR), and the Internet of Things (IoT) present capabilities that can effectively alert both drivers and workers of high-risk situations and even remove workers from hazardous exposures. These systems can broadly be classified into wireless connections from vehicles to vehicles (including construction equipment) (V2V), vehicles to infrastructure (V2I), and vehicles to people (V2P). Their potential benefit to safety in work zones is promising. One such system has been developed and demonstrated by the Federal Highway Administration

6 (FHWA) which relies on cooperative driving automation (CDA) to enhance safety and mobility in work zones (Bujanovic et al. 2021). Specific implementations of emerging technologies that apply to work zone safety include intrusion alert devices and sensors to monitor errant vehicles and other hazardous situations for the worker by tracking the positions of workers and equipment along with the location, speed, and heading of moving vehicles. Additionally, novel visualization technologies like augmented reality have been implemented to supplement worker situational awareness by helping them to better identify, process, and respond to hazards as they navigate the work environment. Both of these classes of technologies, i.e., connected hardware and visualization technologies, provide the opportunity to link predicted hazardous situations identified upstream during the project planning phase to real-time field information during the performance of construction in the work zone to further enhance worker and driver safety. Successful implementation of many of these technologies in practice, along with the accompanying benefits, have been reported (e.g., Cameron, G. 2020; Transportation Professional 2016; Crawford, D. 2014; Sant, B. 2014). The technologies mentioned above have been utilized in various capacities to create intrusion prevention devices to keep vehicles from intruding into the active work area and intrusion alert devices that warn workers of vehicles intruding into work zones (Khan et al. 2019; Gambatese et al. 2017a; Marks 2017; Novosel 2014). Research into their use has highlighted inconsistencies regarding their performance and implementation (Nnaji et al. 2019a). The identified inconsistencies range from a difference in performance of audible alerts to a significant difference in assumed reaction times of workers to these alarms (Thapa and Mishra 2021; Awolusi and Marks 2019; Nnaji et al. 2018). Another limitation highlighted consistently in previous studies is the likelihood of false alarms that can cause alarm fatigue (Louis et al. 2018). Thus, while intrusion prevention and alert technologies show promise for improving work zone safety, concerns about the technologies remain related to inconsistent performance, reaction times, and false alarms, limit their perceived usefulness. In addition, with the variety of technologies available on the market, information and tools are not available to strategically identify and select specific technologies for use on a project. There is a need for guidance on adopting WZITs and selecting technologies for a project based on the particular project, roadway, technology, and work operations characteristics. Having such guidance available will support traffic control designers and contractors with decision-making related to technology selection and use. 1.1 Problem Statement and Research Objectives The current state of the art and practice reveal that several technologies can considerably improve worker safety by connecting a priori information about work zone hazards with real-time information about the workers and equipment. However, there is presently a lack of large-scale adoption of these technologies by roadway contractors. Suggested reasons for the low level of use include inconsistencies regarding their performance and implementation, as well as the conservative and fragmented nature of the industry. Two key factors to successful implementation of these technologies are the initial decision to adopt the technology (to meet an existing need) and then the determination of when, where, how, and to what extent to use the technology for

7 maximum effectiveness. A lack of understanding of these factors and conditions, along with an absence of supporting implementation guidance for project personnel, limit the value and potential positive impact of these technologies. While state DOTs may not prescribe and/or enforce the safety measures to be taken by contractors, DOTs can utilize the study results to inform and aid contractors in their efforts to enhance work zone safety, decide which technologies to adopt, and identify effective implementation opportunities. This research seeks to fulfill the need for guidance on work zone intrusion mitigation technology usage through the pursuit of two specific objectives: 1. Identification of successful applications of existing and emerging technologies to mitigate work zone intrusions; and 2. Development of a technology implementation guide and DSS that helps transportation agencies select and implement technologies to prevent work zone intrusions, and ultimately improve work zone safety. 1.2 Scope of Study The research study aims to synthesize, analyze, and package current information and knowledge about WZITs with the goal of providing guidance for their adoption within a transportation agency, selection for a specific project and/or use, and implementation in practice. For the purposes of the study, work zones are considered to be any temporary traffic control zone on a roadway that is in place to allow for work to be conducted on the roadway. As defined in the Manual on Uniform Traffic Control Devices (MUTCD) (FHWA 2009), a temporary traffic control zone is “an area of a highway where road user conditions are changed because of a work zone or incident by the use of temporary traffic control devices, flaggers, uniformed law enforcement officers, or other authorized personnel.” The MUTCD describes a work zone as “an area of a highway with construction, maintenance, or utility work activities” (MUTCD Section 6C.02). The presence and length of work zones is communicated to the road user through traffic controls and signage. As described in the MUTCD, a work zone is “typically marked by signs, channelizing devices, barriers, pavement markings, and/or work vehicles. It extends from the first warning sign or high-intensity rotating, flashing, oscillating, or strobe lights on a vehicle to the END ROAD WORK sign or the last TTC device” (MUTCD Section 6C.02). The MUTCD definition and description of work zones are utilized for the scope of the study. In addition, temporary work zones of any duration are considered. The study focuses on commercially available WZITs which, if deployed strategically, can potentially prevent an intrusion from occurring and/or mitigating the impacts of an intrusion. WZITs that are applicable to all typical roadway construction and maintenance activities are considered. The technologies may be placed directly on the roadway, on a piece of roadway infrastructure, or on a piece of equipment or worker within the work being undertaken. The technologies may be located before or anywhere within the work zone. The technologies may also rely on connection with the passing motorist, such as the use of Bluetooth to send an alert to a motorist vehicle or mobile phone. In terms of technology functions, the study considered

8 technologies that are designed to prevent an intrusion, detect that an intrusion has occurred, alert workers and motorists of an intrusion, and mitigate the impacts of an intrusion. Technologies are available that are designed for use during traffic control planning and design prior to the presence of the work zone. These types of technologies were not included in the study. Only those technologies that are intended to be used while the work zone is present, and are physically located within or near the work zone, were included. Additionally, only those technologies that are presently ready for adoption and use are considered. Technologies that are aspirational and still being developed are not included in the study scope. The study scope incorporates common practices and considerations within, and technologies that are presently available to, state transportation agencies across the United States. No technologies were excluded based on cost, manufacturer, proprietary, regulatory, or other similar factors. The MUTCD states that intrusion warning devices may be used to alert workers to the approach of errant vehicles (MUTCD Section 6D.03). For the purposes of the study, work zone intrusions are considered as those instances when a public vehicle erroneously enters into a controlled work zone in which workers may or may not be present. Intrusions may occur due to a variety of reasons such as driver error, incorrect or confusing temporary signage, poor maintenance of temporary traffic control, poor environmental conditions, or other roadway, driver, or work operations impacts. Unexpected intrusions by a construction or maintenance vehicle or piece of equipment into an area of the work zone are also considered within the scope of the study. Lastly, the scope of the study incorporated the collection and analysis of information and knowledge that are present within publicly available resources and the transportation and roadway construction community. No effort was included to identify, design, and manufacture new technologies, or test or modify existing technologies to evaluate and/or improve their performance. 1.3 Organization of Report This report provides a comprehensive description of the study activities, data collection and analysis, and conclusions and recommendations drawn from the study. The report contains the guide developed to support practical adoption, selection, and implementation of WZITs, and a description of the DSS created to assist practitioners with decision-making related to WZITs. The report is organized into the following chapters: Chapter 1 Background: This chapter provides background context for the study. It discusses the problem being addressed by the study, current knowledge related to work zone intrusions and intrusion technologies, and the study objectives and scope. Chapter 2 Research Approach: This chapter discusses the methods and approach followed by the research team to address the problem identified, and meet the aims and objectives of the study. The chapter describes the efforts and processes to conduct the literature review and technology evaluation process, online survey, case studies, and creation of the DSS and guide.

9 Chapter 3 Findings and Applications: The results and analysis from each research step described in Chapter 2 are presented in this chapter, along with discussions of the practical application of the findings. It describes the results of the literature review, documentation and evaluation of WZITs, online survey, and technology case studies. The chapter also presents and describes the outputs of the research for use in practice (i.e., DSS and guide). Chapter 4 Conclusions and Suggested Research: The findings and discussions from the previous chapter are consolidated and summarized in Chapter 4. This chapter provides recommendations and successful practices for addressing certain challenges associated with the use of WZITs during roadway construction and maintenance operations. References: This section of the report lists the references cited in the body of the report. Appendices: This section of the report includes the detailed information and documents used and created in the study. Included in the Appendix are the: survey questionnaire (Appendix A), detailed taxonomy of work zone intrusion technologies (Appendix B), case study interview script (Appendix C), case study template (Appendix D), and detailed WZIT case studies (Appendix E).