The Factors Behind Bicycle Fatalities – and Where to Act

Every year, people on bikes are injured or killed on American streets that were not designed with them in mind. The question is no longer whether to invest in bike infrastructure. It’s where, and in what form, because not every corridor carries the same risk.

The growing role of bike lanes in U.S. urban mobility

Vision Zero commitments and Complete Streets policies have pushed cities to rethink how street space gets allocated. But building lanes isn’t the same as reducing risk.

According to NHTSA, 1,166 bicyclists died in U.S. traffic crashes in 2023, a 4% increase over the previous year, and four out of five of those deaths (81%) occurred in urban areas. Where riders and drivers share the same space without clear separation, risk doesn’t disappear. It concentrates. The challenge for city transportation planners is knowing which corridors need structural intervention and which don’t.

When mixed traffic becomes risky

Shared streets aren’t inherently dangerous. On genuinely low-volume, low-speed neighborhood streets, mixed traffic may work.

Some may think that intersections are where bicyclists are most at risk. Federal data says otherwise: NHTSA also reported that 62% of bicyclist fatalities happen away from intersections, along the corridor itself. FHWA attributes nearly a third of fatal and serious-injury bicyclist crashes to a single mechanism: a motorist overtaking a rider, often shaped by two variables:

Speed environment. Research and industry design guidance frequently found operating speed as one of the strongest predictors of bicycle safety risk.
Vehicle mix. Per NHTSA, light trucks (SUVs, pickups and vans) were the vehicle most frequently involved in crashes that killed a bicyclist, in 557 of 1,091 single-vehicle cases. In 85% of those, the bicyclist was struck by the front of the vehicle.

Identifying High-Risk Bicycle Corridors

There’s no universal threshold. Agencies typically evaluate a combination of operating speed, traffic volume, roadway design, vehicle mix, crash history and bicycle activity when determining whether additional separation may be warranted. In some locations, speed management may be sufficient. In others, roadway redesign, intersection improvements, operational changes or physical separation may be appropriate.

Three ways data reveals bike safety hotspots

Risk is not evenly distributed, and national averages often hide the locations where safety challenges actually occur.

Across U.S. cities, bicycle safety outcomes vary significantly depending on roadway design, traffic exposure, land use, and how different users interact with the street. A city can have a relatively low bicyclist fatality rate while still having specific corridors where the combination of speed, traffic volume, and roadway design creates elevated risk.

For transportation agencies, the challenge isn’t simply measuring crashes after they occur. It’s identifying where risk is building before series crashes become common.

1. Identifying where exposure and speed combine.

By layering operating speeds, traffic volumes by user type and time of day, roadway geometry, and crash history, agencies can identify which street segments concentrate risk and where infrastructure investments should happen first.

2. Understanding When and Why Crashes Occur

Crash statistics provide important context, but they rarely identify the exact conditions creating risk. Incorporating near-miss patterns and real-world movement behavior helps reveal how different users interact with the street and when conflicts emerge. The result is not simply identifying that a street is dangerous; it is understanding which segment concentrates risk, at what time, and why. A turning-conflict pattern at one intersection requires a different solution than a high-speed arterial where cyclists share space with vehicles behind only a painted line.

3. Prioritizing the Right Safety Solution

When agencies have access to multiple data sources, like driver behavior, it can change how transportation decisions are made. When operating speeds, traffic exposure, roadway design, crash history, points of interest and user behavior are analyzed together, agencies can determine not only where risk is concentrated, but what intervention is most likely to reduce it. Road Safety Scans help city DOTs, MPOs, and Vision Zero teams understand what is actually happening across their networks, allowing them to prioritize protected infrastructure where it can deliver measurable safety benefits and avoid investing where risk does not justify intervention.

Did it work?

A Before & After Analysis can help answer the question agencies are looking to solve: if a project worked, what was its impact and return on investment and how can it be scaled for future impact.

Want a clearer view of road risk across your network? Book a demo to see how Michelin Mobility Intelligence supports cities, counties and state DOTs.

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