Safe System Approach to Road Safety

According to the latest data from the National Highway Traffic Safety Administration (NHTSA) in February, 2022, 31,720 people died nationwide in motor vehicle crashes from January 2021 through September 2021. This is roughly a 12% increase from the same time period in 2020, and the highest number of fatalities "during the first nine months of any year since 2006 and the highest percentage increase during the first nine months in the Fatality Analysis Reporting System’s history."

In California, according to provisional SWITRS data for 2019, the number of pedestrians killed in 2019 was 1,030, an increase of 48 fatalities from 2017. The number of bicyclists killed in the same period decreased from 164 in 2017 to 157 fatalities in 2019. These losses of life are unacceptable and preventable. As acknowledged in strategies like Vision Zero, Toward Zero Deaths and the Road to Zero, no one should be killed or suffer severe injuries on our roadways and there is a moral imperative to ensure and increase safe, healthy, equitable mobility for all.

To reach the goal of zero deaths on our roadways, traffic safety professionals and advocates have called for changing the way we think about road safety and taking a different approach. In fact, on January 27, 2022 the U.S. Department of Transportation Secretary announced the release of the federal government's new National Roadway Safety Strategy (NRSS), which outlines steps and strategies for traffic safety stakeholders to address this crisis of roadway fatalities and serious injuries. At the core of the NRSS is the U.S. DOT department-wide adoption of the Safe System approach. Visit the new National Roadway Safety Strategy (NRSS) website to access the report and related resources.

The Safe System Approach

Until recently, the expectation that traffic deaths are inevitable was the main focus of approaches to road safety. In order to create safer communities, safety efforts focused on changing human behaviors to prevent crashes and injuries.

The Safe System approach counters this, with safety efforts to save lives instead focusing on the understanding that humans make mistakes, human bodies are fragile, and crashes are likely to happen. Now, attention is refocused on the reduction of fatal and severe injuries when a crash occurs through the use of vehicle or roadway design and the management of our infrastructure.

Safe System Principles

According to the Federal Highway Administration (FHWA), there are six principles that underlie the Safe System Approach:

  • Deaths and injuries are unacceptable: While no crashes are desirable, the Safe System approach prioritizes crashes that result in death and serious injuries, since no one should experience either when using the transportation system.
  • Humans make mistakes: People will inevitably make mistakes that can lead to crashes, but the transportation system can be designed and operated to accommodate human mistakes and injury tolerances and avoid death and serious injuries.
  • Humans are vulnerable: People have limits for tolerating crash forces before death and serious injury occurs; therefore, it is critical to design and operate a transportation system that is human-centric and accommodates human vulnerabilities.
  • Responsibility is shared: All stakeholders (transportation system users and managers, vehicle manufacturers, etc.) must ensure that crashes don’t lead to fatal or serious injuries.
  • Safety is proactive: Proactive tools should be used to identify and mitigate latent risks in the transportation system, rather than waiting for crashes to occur and reacting afterwards.
  • Redundancy is crucial: Reducing risks requires that all parts of the transportation system are strengthened, so that if one part fails, the other parts still protect people.

Safe System ElementsGraphic showing the principles and five elements of a Safe System Approach

A Safe System also addresses every aspect of crash risk through five elements, or layers of protection:

  • Safe Road Users
  • Safe Vehicles
  • Safe Speeds
  • Safe Roads
  • Post Crash Care

Listed below are a selection of resources related to the Safe System Approach to road safety. This page will continue to be updated with resources as we come across new information, so please continue to check our site for updates. Have a resource to share? Please contact us at safetrec@berkeley.edu.

Resources

  • California Safe Speeds Toolkit - This toolkit from UC Berkeley SafeTREC follows the work of the Zero Traffic Fatalities Task Force (ZTFTF) and is intended to help local jurisdictions across California set safer speed limits that accommodate all road users using Safe System principles. This toolkit consolidates key research on Safe Speeds from the ZTFTF Research Synthesis by the University of California Institute of Transportation Studies, provides details on speed limit setting flexibilities under the existing California framework, highlights select speed limit setting case studies from cities across California, and points local jurisdictions toward next steps in pursuing safe speed limit setting.
  • FHWA Safe System Assessment Framework - This guide presents a framework for accessing how well existing infrastructure and road environments align with the Safe System approach. The framework includes all ‘pillars’ of the system, including an assessment of issues relating to the road and travel speeds. It also ensures consideration of other pillars which are typically included less often in infrastructure projects. These include road user issues and vehicle-related issues. Post crash care is also considered.
  • Demystifying the Safe System Approach, Vision Zero Network (VZN) - The Vision Zero network explains the Safe System approach in detail by providing six examples of the approach to street design, ways to use the approach in practice, and resources for future guidance. 
  • What is a Safe System Approach? (OTS) - The Office of Traffic Safety embraces a Safe System approach, which focuses on both human mistakes and human vulnerability, and provides a framework to design a system to protect everyone. Safe roads, safe speeds, safe vehicles, safe road users and post-crash care all reinforce multiple layers of protection to protect everyone.
  • Safe System Strategies for Bicyclists and Pedestrians Toolkit (CPBST) - The Toolkit provides a starting point for anyone looking to plan a bikeable and walkable community. It lists potential community improvements that can help create a safer community with the Safe System Approach. 
  • National Roadway Safety Strategy (NRSS) - The U.S. Department of Transportation released the NRSS in January, 2022. The strategy outlines the Department’s adoption of the Safe System approach to significantly reducing serious injuries and deaths on our Nation’s highways, roads, and streets. 
  • Zero Deaths - Saving Lives through a Safety Culture and a Safe System (FHWA) - The FHWA adopted the Zero Deaths vision, influenced by the Vision Zero strategy, which recognizes that even one death within our transportation systems is unacceptable. All road users deserve safe mobility options and the Safe System approach is how to get there.
  • Safe System Resources (ITE) - The ITE’s Safe System webpage contains an explanation, framework and resources on the Safe System Approach. ITE created the webpage alongside the Road to Zero Coalition and members of the RTZ Safe System Working Group
  • Vision Zero Network (VZN) - The VZN helps communities across the United States address traffic deaths and injuries. Based on the Vision Zero strategy, the VZN aims to eliminate all traffic deaths and injuries across the United States while increasing safe, healthy, equitable mobility for all.
  • Road to Zero: A Plan to Eliminate Roadway Deaths (NSC/Road to Zero Coalition) - The Road to Zero creates a plan to eliminate roadway deaths across the United States by 2050. The coalition created a report to help guide their work to reach zero roadway deaths and encourage anyone to join their coalition.
  • Toward Zero Deaths - Toward Zero Deaths is a strategy to eliminate all serious injuries and deaths on our highway systems nationally.
  • Safe Systems and the role of systems science (CSCRS) - Safe Systems and system sciences are interwoven strategies that the Collaborative Sciences Center for Road Safety (CSCRS) applies to their work in order to reduce traffic injuries and deaths. The CSCRS web page explains the principles for each strategy and how they work together.
  • Safe System Approach and Vision Zero (ACTC) - The Alameda County Transportation Commission's Safe System Approach webpage provides resources on safety best practices and examples of implementation of projects that utilize the Safe System Approach and Vision Zero principles.
  • Safe System Approach to Speed Management Database Map (ITE) - The Safe System Approach to Speed Management database map is an interactive tool that identifies several communities that are applying elements and principles of the Safe System Approach to improve safety through speed management. It includes system, program, policy, and project practices through the lens of the Safe System Approach as a means to reducing and eliminating serious and fatal injury crashes. 

Publications, Reports

  • Building Momentum for a Safe System Approach to Reduce Road Traffic Injuries in the United States (June, 2024): This report from the American Public Health Association presents the history of Vision Zero and the Safe Systems approach in the United States, as well as why the United States has been slow to implement them.

  • Advancing traffic safety through the safe system approach: A systematic review (May, 2024): This systematic review, conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, analyzes 82 relevant studies categorized based on the SSA pillars: safe road users, safe vehicles, safe speeds, safe roads, and post-crash care. The review provides insights into SSA's effectiveness in reducing road traffic fatalities and injuries, exploring implementation challenges and opportunities, including policy initiatives, institutional frameworks, and stakeholder collaborations.
  • Creating a Cultural Maturity Model to Assess Safe System Readiness Within Road Safety Organisations (February, 2024): This study proposes the creation of a Safe System Cultural Maturity Model (SSCMM), where it can assess how culturally mature organisations are in relation to Safe System thinking and application. The researchers assert the importance of understanding how far along road safety authorities are in their adoption of Safe System principles, as well as identifying where further support is required.
  • A Safe System Guide for Transportation: Sharing this Approach to Lead Your Community to Action (November, 2023): This report from the AAA Foundation for Traffic Safety presents recommendations for framing Safe System interventions to facilitate public acceptance and support.
  • The Most Vulnerable User: Examining the Role of Income, Race, and the Built Environment on Pedestrian Injuries and Deaths (June 2023): This study examined the incidence of injurious and fatal pedestrian crashes for lower-income and affluent communities in Broward and Palm Beach counties, FL, finding notable differences in the environmental risk factors for these populations. The study's results suggest that pedestrian crash risk, like much else in U.S. society, is strongly intertwined with broader issues of racial and income inequality. Attempts to address the safety of the transportation system’s most vulnerable users need to move beyond asserting that any pedestrian project constitutes a safety enhancement, and to begin to more meaningfully account for social vulnerabilities associated with race and income.
  • The Safe Systems Pyramid: A new framework for traffic safety (September, 2023): In this article, the authors propose a new framework "for prioritizing policies and interventions, known as the Safe Systems Pyramid, that contains five ascending levels – Socioeconomic Factors, Built Environment, Latent Safety Measures, Active Measures, and Education." This framework is designed to shift the thinking of engineers, planners, and policy makers that shape the transportation system. 
  • Safety Report for Speed Management - This report will help practitioners understand the impacts of speed on traffic safety and explore the link between speed management and the Safe System Approach by introducing a five-stage framework on the Safe System Approach for Speed Management.
  • SafeTREC 2023 Traffic Safety Fact Sheets - SafeTREC releases fact sheets which features traffic safety data and trends at the national and state level on a variety of road safety topics, with a focus on the Safe System approach.
  • National Roadway Safety Strategy (NRSS) - The U.S. Department of Transportation released the NRSS in January, 2022. The strategy outlines the Department’s adoption of the Safe System approach to significantly reducing serious injuries and deaths on our Nation’s highways, roads, and streets.
  • FHWA Public Roads, Winter 2022. This special edition of the Federal Highway Administration (FHWA) Public Roads magazine features a series of articles about the Safe System approach to road safety, including topics such as the Highway Safety Improvement Program (HSIP), speed management, application of the Safe System, evaluating intersection designs according to the Safe System, and more. 
  • Putting the Pieces Together: Addressing the Role of Behavioral Safety in the Safe System Approach (2021) - Cambridge Systematics' report, developed in partnership with the Governor's Highway Safety Association, provides guidance to State Highway Safety Offices (SHSO) on highway safety planning and implementing behavioral safety measures within the Safe System approach. The report provides a framework for how SHSOs and their partners can effectively integrate behavioral safety and the Safe System approach across SHSO operations and programs.
  • Recommendations of the Safe System Consortium (2021) - The Consortium’s report details their recommendations to reimagine road safety and equity in the United States. The recommendations set forth by the Consortium aim to change the course of safety on our roads and create more equitable transportation systems.
  • Safe System Strategic Plan (2021) - The Road to Zero Coalition created the Safe System Strategic Plan in order to create a guide for the strategies, focus areas, measures of success and specific actions needed for infrastructure owners and operators in the United States to fully adopt the Safe System Approach. The plan aims to change mindsets, scale and practices through the education of decision makers, influences and practitioners.
  • The Road to Zero: A Vision for Achieving Zero Roadway Deaths by 2050 (2018) - The Road to Zero report creates a vision of a world where no roadway deaths occur by the year 2050. By envisioning a safer future, we can work together to inform and coordinate traffic safety efforts in the present.
  • Shared Responsibility for Road Safety in Safe Systems Context (2018) - This fact sheet from UC Berkeley SafeTREC discusses a principle integral to a Safe Systems Approach, shared responsibility for road safety.
  • The Goal of Road Safety in the Safe Systems Context (2018) - This fact sheet from UC Berkeley SafeTREC provides an overview of the Safe Systems Approach and how it relates to both current road safety practice and initiatives such as Vision Zero.

International Resources

  • The Safe System Approach (PIARC) - PIARC’s (World Safety Association) road safety manual, based on the Safe System Approach, allows countries worldwide to create transportation systems that are free of traffic deaths.
  • Safe System Principles (National Road Safety Strategy, Austraila) - Australia’s National Road Safety Strategy, based on the Safe System Approach, provides the principles needed to create safer mobility for all. 
  • Sustainable & Safe: A Vision and Guidance for Zero Road Deaths (WRI, GRSF) - The World Resources Institute and Global Road Safety Facility created this report to create the vision and guidance needed in order to achieve zero road deaths globally.

Events, Trainings, Programs

Community Approaches

  • Conducting Community Engagement with a Safe System Lens (SafeTREC) - Few resources, if any, address how to apply the Safe System framework in community engagement and planning efforts. In this brief, UC SafeTREC and Cal Walks demonstrate how they adapted FHWA’s Safe System elements and principles to not only make it more applicable for grassroots community engagement but also to strengthen the impact of the approach.

Safe System In Practice