Accident Trends and What They Tell Us

Total e-bike sales grew roughly 6x from 2019 to 2024. ED visits grew roughly 7x. So per-bike crash exposure is rising slightly, not exploding — but the absolute number of injuries is large and growing.

Per-mile crash rates for e-bikes run approximately 2.5x rates for regular bicycles in the few studies that have rigorously controlled for exposure. The drivers are higher average speeds, larger share of new-to-cycling riders, and increased use in mixed-traffic conditions where bike infrastructure hasn't caught up.

Upper extremity fractures (wrist, elbow, clavicle) from low-speed falls — typically a rider losing balance at a stop or a slow cornering crash. These rarely cause permanent disability but generate the largest count of ED visits.

Head injuries — concentrated in unhelmeted riders. The mortality difference between helmeted and unhelmeted e-bike crashes in serious-injury cohorts is roughly 4x. Helmet use is the single biggest determinant of how a bad crash ends.

Lower extremity fractures and pelvic injuries — typically from side-impact car collisions at intersections. These are the highest-severity, lowest-frequency category.

Helmet always — 41-47% reduction in serious head injury depending on the study. Daytime running lights always — ~47% reduction in crashes involving cars. Choosing routes with protected infrastructure where available — ~35% reduction. Matching bike speed to the riding environment — hard to measure but qualitatively the single most controllable factor.

What doesn't measurably help: hi-vis vests alone (without lights), reflective frame stickers, bike-mounted mirrors. These are not bad — they're just not where the leverage is.