By: Mark Doctor, FHWA Resource Center; Chimai Ngo, Norah Ocel, Karen Scurry, and Jeff Shaw, FHWA Office of Safety

Traffic fatalities in the United States have remained fairly constant since 2015. To reach our goal of zero traffic deaths, we need to change the way we think about traffic safety.

We need to adopt a Safe System approach.

The Safe System approach was founded on the principle that no one should be killed or injured when using the road system. While no roadway crash is desirable, the Safe System approach focuses on crashes that result in deaths and serious injuries.

The approach is gaining momentum through parallel initiatives around the country, including Vision Zero, Toward Zero Deaths, and Road to Zero. Although comprised of different stakeholders, all three efforts share the vision of eliminating fatalities and serious injuries on the Nation's roads, and they are beginning to implement the Safe System approach in different contexts. With Vision Zero, local communities are applying the Safe System approach with a focus on speeds, especially for vulnerable road users. States have adopted zero-deaths goals in their Strategic Highway Safety Plans (SHSP), using the Safe System framework from the report, Toward Zero Deaths: A National Strategy on Highway Safety. Under the leadership of the National Safety Council, the Road to Zero Coalition adopted three strategies; among them is "prioritize safety," which addresses the Safe System approach and safety culture.

At the core of the Safe System approach is acknowledgement that road users will inevitably make mistakes, and those mistakes can lead to crashes. Foundational to the Safe System approach is the expectation that the roadway system is planned, designed, and operated to be forgiving of inevitable human errors so that injury outcomes are unlikely to occur. This requires understanding that the human body has limits on its ability to withstand crash impacts before deaths and serious injuries occur.

Applying the Safe System approach involves anticipating human mistakes by designing and managing the road infrastructure to keep the risk of mistakes low, and to ensure that when mistakes lead to a crash, the impact energy on the human body stays at tolerable levels. There are six principles of the Safe System approach:

• Deaths and serious injuries are unacceptable – No one should be killed or injured when using the road system. The Safe System approach attempts to bring a public health-type focus to road safety, with emphasis on minimizing the harm of crashes. Successfully adopting the Safe System approach requires a safety culture that unequivocally places safety first and foremost in our road system investment decisions.
• Humans make mistakes – People will inevitably make mistakes, and those mistakes can lead to crashes. The Safe System approach expects the road system is planned, designed, and operated to be forgiving of inevitable human errors, so that injury outcomes are unlikely to occur.
• Humans are vulnerable – People have a limited ability to tolerate crash impacts. Although the exchange of kinetic energy in collisions among vehicles, objects, and people has multiple determinants, applying the Safe System approach largely depends on managing the kinetic energy of crashes to avoid injury outcomes.
• Responsibility is shared – Road users, vehicle manufacturers, road designers and operators, law enforcement, and post-crash care providers all share responsibility to ensure that crashes do not lead to fatal or serious injuries. As part of a shared responsibility for safety, road users are expected to comply with traffic laws. Education, enforcement, and vehicle feedback components (e.g., speedometer and automated driving systems) are all critical in enabling and encouraging safe road use.
• Safety is proactive – Tools can be used to identify and mitigate risks in the road system to proactively prevent crashes, rather than react after crashes occur.
• Redundancy is crucial – With shared responsibility comes inter-relationships and opportunities for synergy. Weaknesses in one area of the system may be compensated with enhancements in other areas. For example, intersection geometry design could correlate to occupant-protection features offered in current vehicle design. Timely and effective emergency response when crashes do occur is also a critical element of a Safe System. Redundancy helps ensure that if one part of the system fails, other parts still protect road users from death or serious harm.

A commitment to zero traffic deaths also means addressing all aspects of safety through the following five elements that, together, create a holistic approach with layers of protection for road users:

• Safe Road Users – The Safe System approach addresses the safety of all road users, including those who walk, bike, drive, ride transit, and travel by other modes.
• Safe Vehicles – Vehicles are designed and regulated to minimize the frequency and severity of collisions using safety measures that incorporate the latest technology.
• Safe Speeds – Humans are unlikely to survive high-speed crashes. Reducing speeds can accommodate human-injury tolerances in three ways: reducing impact forces, providing additional time for drivers to stop, and improving visibility.
• Safe Roads – Designing to accommodate human mistakes and injury tolerances can greatly reduce the severity of crashes that do occur. Examples include physically separating people traveling at different speeds, providing dedicated times for different users to move through a space, and alerting users to hazards and other road users.
• Post-Crash Care – People who are injured in collisions rely on emergency first responders to quickly locate and stabilize their injuries and transport them to medical facilities. Post-crash care also includes forensic analysis at the crash site, traffic incident management, and other activities.

We all have a role in implementing the Safe System approach to save lives and reach our shared goal of zero deaths. Consider applying a Safe System lens to upcoming projects and plans in your community. Put safety at the forefront and design to accommodate human mistakes and injury tolerances.

FHWA has several efforts underway to help you on your Safe System journey, including:

• Developing marketing materials to help raise awareness of Safe System in the United States. The materials include a flyer, presentation (available fall 2020), and video (available winter 2021).
• Exploring the relationship between Safe System and the Highway Safety Improvement Program (HSIP). A final report (available fall 2020) will identify areas of alignment, as well as opportunities and noteworthy practices to help States integrate Safe System with our existing safety programs.
• Assisting Vision Zero communities and States to coordinate their zero-deaths efforts through the Safe System approach. A report (available fall 2020) will present strategies to coordinate zero-deaths efforts among State, regional, and local agencies.
• Assisting Vision Zero communities to integrate the Safe System approach in their action-planning process. A report (available winter 2021) will document the Vision Zero communities' safety planning processes.
• Establishing a Safe System framework for intersections. This project, A Safe System Approach to Intersection Planning and Design in the United States (to be completed in winter 2021), will present a methodology that explicitly incorporates Safe System principles to vet different intersection design and control alternatives. The methodology will be sensitive to exposure, severity, and complexity, and it will rely on inputs commonly available during project development. This initial framework will dovetail with stage 1 of Intersection Control Evaluation (ICE) procedures, which is typically the planning or scoping stage of an intersection project.
• Partnering with the Institute of Transportation Engineers to develop a Safe System Strategic Plan for the United States (to be completed in winter 2021).
• FHWA is continuing to advance the Safe System approach, through these and other efforts, to reach zero deaths. Visit /safety/zero-deaths to keep up to date on current and future Safe System activities.

For more information, please contact Chimai Ngo at chimai.ngo@dot.gov.