Integrating complex systems science into road safety research and practice, part 1: review of formative concepts.

Many of our most persistent public health problems are complex problems. They arise from a web of factors that interact and change over time and may exhibit resistance to intervention efforts. The domain of systems science provides several tools to help injury prevention researchers and practitioners examine deep, complex and persistent problems and identify opportunities to intervene. Using the increase in pedestrian death rates as an example, we provide (1) an accessible overview of how complex systems science approaches can augment established injury prevention frameworks and (2) a straightforward example of how specific systems science tools can deepen understanding, with a goal of ultimately informing action.

Integrating complex systems science into road safety research and practice, Part 2: applying systems tools to the problem of increasing pedestrian death rates.

OBJECTIVES: To provide a specific example of how systems dynamics tools can increase understanding of stakeholder 'mental models' and generate robust systems-based hypotheses about the escalating problem of rising pedestrian death rates in the USA. METHODS: We designed and facilitated two group model building (GMB) workshops. Participants generated causal loop diagrams (CLDs) individually and in small groups to explore hypotheses concerning time-dynamic interacting factors underlying the increasing rates of pedestrian deaths. Using a grounded theory approach, research team members synthesised the structures and hypotheses into a single CLD. RESULTS: CLDs from the 41 participants indicated four core factors hypothesised to have a direct impact on pedestrian fatalities: pedestrian-vehicle crashes, vehicle speed at the time of the crash, vehicle size/dimensions and emergency response time. Participants diagrammed how actions and reactions impacted these proximal factors over time and led to ripple effects throughout a larger system to generate an increase in pedestrian deaths. Hypothesised contributing mechanisms fell within the following broad categories: community responses; research, policy and industry influence; potential unintended consequences of responses to pedestrian deaths; and the role of sprawl. CONCLUSIONS: This application of systems science tools suggested several strategies for advancing injury prevention research and practice. The project generated robust hypotheses and advanced stakeholder communication and depth of understanding and engagement in this key issue. The CLD and GMB process detailed in this study provides a concrete example of how systems tools can be adopted and applied to a transportation safety topic.

Diverse school community engagement with the North Carolina active routes to school project: a diffusion study.

BACKGROUND: Schools located in rural parts of the United States and North Carolina have benefited proportionally less from the federal Safe Routes to School (SRTS) program than their more urban counterparts. We investigated whether and how diverse elementary and middle school communities throughout North Carolina have engaged in a SRTS-inspired, multi-sectoral initiative called the Active Routes to School (ARTS) project over the course of 5 years (2013 through 2017). METHODS: Analyses included a study sample of 2602 elementary and middle schools in North Carolina, 853 that participated in the ARTS project over the five-year study period and 1749 that had not. Statistical models controlling for county- and school-level confounders predicted schools' involvement in walking and bicycling-promotive events, programs, and policies over time. RESULTS: Schools' engagement with ARTS Project programming increased significantly over the study period, with 33% of eligible schools participating with the project by the end of 2017. Participation was most common in promotional events. Such event participation predicted engagement with regularly recurring programming and school- and district-level establishment of biking- and walking-facilitative policies. Lower income schools were more likely to establish recurring bike and walk programs than wealthier schools, whereas rural schools were less likely than city schools to participate in promotional events, yet equally as likely as other schools to participate in recurring bike and walk programs. CONCLUSIONS: Schools' engagement with the North Carolina ARTS Project diffused despite many schools' rural geographies and lower socioeconomic status. Further, participation in one-time promotional events can portend schools' establishment of recurring walking and biking programs and supportive policies.

Systems thinking in the context of road safety: Can systems tools help us realize a true "Safe Systems" approach?

PURPOSE OF REVIEW: Road traffic injuries are one of the leading causes of death in the U.S. and globally. We introduce the Safe Systems approach as a promising paradigm for road safety practice and describe how systems thinking tools can help bridge the gap between the current status quo and a Safe Systems approach. RECENT FINDINGS: Systems thinking tools can help us align with a Safe Systems approach by identifying latent risks in the transportation system, examining factors that coalesce to produce high travel speeds and kinetic energy transfer, and supporting safety prioritization through goal alignment. SUMMARY: The Safe Systems approach represents a significant change in the way we have historically designed transportation systems; it puts safety at the forefront and calls for designing a system that accounts for human fallibility. Operationalizing holistic Safe Systems concepts may be difficult, but systems thinking tools can help. Systems thinking tools provide a common language for individuals from diverse disciplines and sectors to express their unique understanding of the interconnected factors shaping road safety problems and support discussions about potential solutions that align with a Safe Systems approach.

Organizational networks in road safety: Case studies of U.S. Vision Zero cities.

Objective: Each year, more than 30,000 deaths occur on U.S. roads. Recognizing the magnitude and persistence of this public health problem, a number of U.S. cities have adopted a relatively new approach to prevention, termed Vision Zero (VZ). VZ has been adopted by more than 30 U.S. cities and calls for creating a transportation system that ensures that no road traffic crash results in death or serious injury. A core component of VZ is strong multidisciplinary and multisector stakeholder engagement, and cities adopting VZ often establish a VZ coalition to foster stakeholder collaboration. However, there is little information on the structure, development, and functioning of coalitions working to achieve VZ and on tools available to study and evaluate such coalition functioning. We sought to describe the characteristics of prominent U.S. VZ city coalitions and context surrounding VZ uptake and advancement in these cities. Moreover, we demonstrate use of network analysis as one tool for exploring the structure of interorganizational relationships in coalitions. Methods: We conducted case studies of 4 prominent U.S. VZ city coalitions in 2017-2018. We summarized coalition members' characteristics and responses to questions about their cities' VZ adoption, planning, and implementation. We asked each coalition member to provide information on their contact frequency, perceived productivity, and resource sharing with every other coalition member in their city and used network analysis techniques in 2 cities to understand the structures and relationships in coalitions. Results: Findings indicated that government agencies generally constituted the majority of coalition members and often played central roles in terms of coalition network contact, productivity, and resource flow. Other emerging similarities regarding coalition establishment and VZ implementation included the need for political support, the importance of formal plan development, and increased collaboration and cooperation among partners. Conclusions: Organizational network analyses, enriched with coalition member interviews, can elucidate key aspects of coalition creation, attributes, and relationship structure. The case studies of leading VZ coalition networks presented here highlight the use of these tools. Ultimately, understanding associations between VZ network structures and attributes and road safety outcomes could help inform effective coalition adoption, implementation, and maintenance to optimize safety outcomes.

Awareness of Vision Zero among United States' road safety professionals.

BACKGROUND: Vision Zero is a strategy to eliminate all fatalities and serious injuries from road traffic crashes, while increasing safe and equitable mobility for all. In 2015, the United States' Department of Transportation announced the official target of the federal government transportation safety policy was zero deaths. In 2017, we assessed the dissemination of Vision Zero in the United States. METHODS: We conducted a web-based survey in 2017 among road safety professionals. Email invitations were sent using relevant membership directories and conference lists. RESULTS: We surveyed 192 road safety professionals, including planning/engineering (57.8%), public health (16.7%), and law enforcement/emergency medical services (EMS) (8.9%). Awareness of Vision Zero was higher among planning/engineering fields (97.3%) compared to law enforcement/EMS (76.5%) and public health (75.0%). Awareness was similar by number of years working in the field. Awareness was higher in the South (95.9%) and Northeast (95.0%) regions, followed by the West (90.8%) and Midwest (85.2%) Census regions. Among those that heard of Vision Zero (n = 174), 41.8% worked at a municipality with a Vision Zero campaign, while 41.2% did not. Among those working at a municipality with a Vision Zero campaign (n = 71), about half participated in the campaign (54.9%) while the other half did not (45.1%). CONCLUSIONS: With widespread dissemination of the Vision Zero strategy to road safety professionals, next steps include evaluating how Vision Zero is being adopted, implemented, and maintained in communities, as well as the awareness and acceptability by community members, and to identify the most promising policies and practices.

Diffusing innovative road safety practice: A social network approach to identifying opinion leading U.S. cities.

OBJECTIVE: This study sought to identify opinion-leading U.S. cities in the realm of safe transportation systems by surveying road safety professionals and asking them to identify places that served as models for road safety. METHODS: Using a purposive sampling methodology, we surveyed professionals employed in road safety-related professions (e.g., transportation engineering, planning, public health, law enforcement, and emergency response). Using 183 professionals' complete responses, we carried out social network analysis to both describe the structure of intermunicipal advice-seeking patterns among road safety professionals and identify those municipalities with relatively high degrees of influence. RESULTS: We discovered a large intermunicipal monitoring network related to improving road user safety. Half of the network ties (50.4%) crossed regional U.S. census boundaries. Social network statistics informed the identification of 7 opinion-leader and 4 boundary-spanning municipalities. CONCLUSIONS: This study indicated a large intermunicipal monitoring network, half of which crossed regional boundaries. Road safety professionals have formed a country-spanning example-following network on the topic of improving road user safety in the United States. Researchers and intervention teams can tap into this network to accelerate the uptake and spread of evidence-based road safety practices.