Motor Vehicle Safety: Engineering Solutions and Beyond

Safe Mobility: Challenges, Methodology and Solutions Edited by Dominique Lord and Simon Washington

Bingley, UK: Emerald Publishing Limited; 2018 512 pages; $134.95 ISBN-13: 978-1786352248

Ever since automobiles became the dominant form of transportation in the early 20th century, motor vehicle injuries have been a significant public health problem. Each year, more than 30 000 people perish in motor vehicle crashes in the United States.¹ On a global scale, more than 1.25 million people die annually in motor vehicle collisions across the planet.² Motor vehicle crashes are the second leading cause of injury-related death in the United States and are on track to become the seventh leading cause of death globally by 2030.^2,3 Given trends that indicate future increases in motor vehicle injuries and the advent of emerging areas that will fundamentally change transportation systems—such as autonomous vehicle technologies and climate change—it is essential that we work quickly and effectively to enhance road safety around the world.

Written by an international cadre of more than 30 authors, Safe Mobility: Challenges, Methodology and Solutions contains 20 chapters that are organized into six major sections. The first five sections focus on driver behavior, the transport network, vulnerable road users, methods for understanding and predicting safety performance, and methods for evaluating the safety effects of countermeasures. In the sixth and final section, the book’s editors, Dominique Lord and Simon Washington, discuss conclusions and future directions. Each chapter within the book is structured as a miniature literature review, complete with a useful abstract at the beginning that summarizes the purpose, methodology, findings, and implications that are discussed therein.

STATE-OF-THE-PRACTICE GUIDANCE

The editors explicitly state the book’s purpose in their introductory chapter: “This book is devoted to presenting a thorough review of what is currently known about global road safety . . . The intent of the book is to provide a broad, yet detailed reference that presents state-of-the-practice guidance regarding both academic and practical knowledge in transport network safety.”^(p3) Overall, the editors’ goal of creating a “detailed reference” is largely achieved. Authors of the individual chapters provide extensive, well-written discussions and references to support their arguments. Albeit informative, Safe Mobility is undoubtedly a reference book that is for engineers, by engineers.

Overall, the book focuses on the effects of specific engineering treatments related to road safety. However, engineering is only one of the six E’s commonly referenced in transportation safety. The E’s also include elements such as education, enforcement, evaluation, encouragement, and equity.⁴ Although the E’s are most often used in reference to pedestrian safety, they are also relevant to the larger field of road safety. The E’s remind us that safety cannot be fully achieved by focusing on one singular element; rather, well-rounded and holistic approaches are necessary to sufficiently protect travelers along transportation networks.

The authors do an excellent job of describing statistical methods that engineers use to quantify the effects of engineering countermeasures, including “before-after evaluations”—the “gold standard” to ascertain the effects of site-specific infrastructural treatments^(p409)—and meta-analytic methods, which synthesize large sets of numerical research results. However, as an evaluator, I found myself wanting to learn how these quantitative methods have and could be paired with qualitative data collection methods to enhance the depth and utility of engineering evaluations. Feedback from road users collected through semistructured interviews, focus groups, and Photovoice projects can provide invaluable data that give context to quantitative findings. Answers to questions such as, “As a pedestrian, where would crossings be most convenient for you on this road?” and “While driving, if you saw a flashing red light at a pedestrian crossing, how would you respond?” can shed light on the potential use, benefit, and value of specific engineering projects. Understandably, qualitative data collection and analysis may not be in the standard traffic engineer’s wheelhouse. However, this is where partners in fields such as public health and community development can be assets and can enhance engineering evaluations.

SAFETY BEYOND ENGINEERING

Because of its narrow focus on engineering, the book misses an important opportunity to provide readers with a broader understanding of the larger effects and influences on road safety beyond specific engineering treatments and countermeasures. For instance, in chapter 10, “Providing for Pedestrians,” the author closes with a discussion of crossing streets as the major safety issue for pedestrians. The proposed solution? Narrow cross-sections and speed cushions at crossing points, which are “key to safety.”^(p226) Authors of chapter 11, “Providing for Bicyclists,” go slightly further to conclude that “political support and leadership are necessary to support campaigns that legitimise cycling as an important form of sustainable transport that is deserving of quality infrastructure and strong investment.”^(p248) However, neither chapter includes current efforts to protect vulnerable road users on a larger scale. For example, the authors do not mention the Complete Streets movement—a US policy initiative involving more than 1300 local, regional, and state agencies and governments that have adopted policies that direct transportation planners and engineers to routinely design and operate roads to ensure safe access for all users.⁵ Also notably missing is Vision Zero,⁶ an international and multidisciplinary strategy that strives to “eliminate all traffic fatalities and severe injuries, while increasing safe, healthy, equitable mobility for all.” Vision Zero efforts involve cross-disciplinary collaborations among local traffic planners and engineers, policymakers, and public health professionals. Through Vision Zero, professionals are working together across sectors to make streets safer by addressing roadway design, speed management, road user behaviors, technology, and policy.⁶

The chapter where you most want the editors to bring it all together—“Summary and Conclusions”—is unsatisfyingly brief. The editors outline several challenges to quantifying and understanding crash risk in transportation networks, including the rarity of road crash events relative to time spent driving; the difficulty of ascertaining actual causes of crashes; the challenges of understanding to what degree driver behavior is to blame for crashes; and the ongoing struggle of protecting pedestrians and bicyclists on roads primarily built for motor vehicles. However, the challenges of ensuring safe mobility go much further. If we accept that road safety is indeed a public health issue, then it must follow that it should be addressed through the lens of public health’s core functions: (1) assessment (monitoring, diagnosing, investigating, and evaluating health problems, hazards, and services), (2) policy development (developing and enforcing policies, laws, and regulations to ensure health and safety), and (3) assurance (educating, empowering, and mobilizing communities to identify and solve health problems). Through a public health lens, making infrastructural changes and engineering modifications to roadways are just one small part of the answer.

Solutions to issues of road safety must go beyond specific engineering treatments to include changes in policies, systems, and environments that collectively contribute to inequitable and dangerous roads. Comprehensive, effective, and sustainable changes require multidisciplinary partnerships and collaborative efforts from professionals working in all aspects of road safety—not just engineers, but also professionals working in public health, planning, policy, law enforcement, and community mobilization. When we acknowledge that each of these professionals has a meaningful role to play—and we ensure that they can consistently collaborate as a natural part of their daily work—only then will we be able to one day achieve safe and equitable mobility for all road users.