The absence of crashes does not equal the presence of safety

Police-reported crash data tells only part of the safety story, and the risks that people walking and biking face on our roadways are potentially much higher than the numbers show. To address safety needs, performance measures and management systems cannot simply respond to crash data alone.

A pedestrian runs across the street as cars with bright headlights near their path
(Christian Lue, Unsplash)
This guest post is a supplement to the 2024 edition of Dangerous by Design, our landmark report on the alarming increase in people being struck and killed while walking, and how the way we design our streets is part of the problem. More than 7,500 people were struck and killed while walking in 2022, marking a 40-year high and a 75 percent increase since 2010.

Read the full report here

The information and recommendations provided in SGA’s Dangerous by Design are important, but the risk posed to people walking and biking is potentially even higher than what is reported. It is generally believed that when a crash occurs on our streets, law enforcement officers quickly arrive on the scene, determine the crash’s cause and the at-fault parties, identify any property damage or injuries among those involved, and file a comprehensive report, which is then reflected in national reports and data. Unfortunately, police-reported crashes—especially those involving pedestrians and bicyclists—only tell us a small part of the safety story. Here are a handful of reasons the absence of police-reported crashes does not equal the presence of safety for road users.

  1. First, at least half of all pedestrian and bicyclist crashes are underreported to police, not equitably distributed across socioeconomic and racial/ethnic lines, with higher hospital admission rates—and lower police-reported crash rates—for injuries sustained by those who are Black or Hispanic compared with those who are white.
  2. Reporting officers often misdiagnose the severity of crash injuries. For example, if a bicyclist appears uninjured at the crash scene, a crash report might not be filed. However, later, the bicyclist might realize they are injured and visit the emergency room, where the event is only captured in emergency department data.
  3. Reported crashes tell us nothing about the ways auto-centric infrastructure suppresses people’s desire to access places on foot or by bicycle. Dangerous streets and intersections for pedestrians and bicyclists—those with multiple lanes of high-speed traffic and wide intersections that invite fast-turning motor vehicles—tend to be places people avoid at all costs. Concluding “there is no safety problem here” when there are no police-reported crashes in an area is simply wrong.  Let’s be clear: if drivers are traveling above 20 mph; if there are poor sight lines around curves or at intersections; if there is no option for a person to safely and comfortably cross the street, there is a safety problem here.
  4. Relying solely on the number of crashes on the network obscures the fact that crash injury outcomes are not the same for everyone. For example, 70-year-olds are roughly five times more likely to die when struck by a driver going 20 mph than are 20-year-olds.
  5. When road safety is evaluated based on data other than the actual injuries that occurred, there is a tendency to mistake trends in crash reporting with trends in traffic safety.

It’s increasingly clear that police-reported crash data tell us only part of the safety story. Therefore, to improve our understanding of community members’ experiences with road trauma, let’s stop equating crash trends with safety and start to:

  • Identify injury risk throughout the network. Land uses and demographics tend to change more rapidly than our street infrastructure. Plodding our way through fixing hot spots and corridors while crashes and injuries move to other places in the network is akin to chasing our tails. We should reference hot spots and high injury networks to remind us of those design features that present injury risk to people operating outside of motor vehicles, read: anywhere traffic speeds are above 20 mph.
  • Directly engage with people in the community who live or work in the riskiest environments about their near misses, actual crashes, or witnessed crash experiences. Also, explore with them those areas they would not dare walk or bike along or try to cross. These areas are likely suppressing walking and biking activity and posing danger to those who lack choices in where and how they get around.
  • Include trauma center, emergency medical services (EMS), and hospital injury data into our surveillance systems. As we shared earlier, a lot of crashes involving pedestrians and bicyclists are not captured in police-reported crash data. A public health approach to injury surveillance means incorporating health system injury data into our performance measurement and management systems. Doing so gives us a clearer sense of the total level of trauma experienced on our streets. It also allows us to better understand the effects our land use policies and street interventions have on local road trauma over time.
  • Employ vehicle operating speeds as a key performance measure. Use vehicle operating speeds to assess risk on segments, at intersections, along corridors, and across networks. In fact, operating speeds could entirely replace level of service (LOS) performance regimes (both driver and multimodal). Why? Because LOS continues to focus on travel time, user delay, and mobility. Speed focuses on the survivability of collisions in the inevitable event that road users make mistakes or misjudgments.

As shared before, places are dynamic. Our world is constantly changing. Our performance measures and management systems need to adjust alongside it. We can’t continue chasing our tails, waiting for underreported crashes to manifest. We must anticipate bad things happening in risky environments, cease perpetuating the development of risky environments through our land development policies and practices, and proactively address our safety problems by slowing down the cars.

Seth LaJeunesse's headshot, short brown hair and glasses with a blue collared shirt, with leaves in the background

Seth LaJeunesse is a Senior Research Associate with the University of North Carolina Highway Safety Research Center (UNC HSRC) where he draws from social and systems sciences to design studies that facilitate the implementation of travel mode shift and Safe System innovations. Seth serves as Principal Investigator (PI) on several federal, foundation, and state research and practice endeavors, and is an active member of the Institute of Transportation Engineers (ITE), the Association of Pedestrian and Bicycle Professionals (APBP), and the Transportation Research Board’s Pedestrians (ACH10) and Transportation Safety Management Systems (ACS10) Committees.


Complete Streets Transportation