Bike crashes in the dark with no street lights are about seven times as often fatal
Of bike crashes in the dark on unlit roads, 9.5% killed the rider (138 of 1,456), against 1.3% in all other lighting (718 of 55,543).
The numbers
- Dark, no street lights
- Other lighting
Cycling crashes, 2021–2026 (2026 so far). Found in 2021–2023 (11% vs 1.5%); held in 2024–2026 (7.7% vs 1.1%).
What it doesn't say
Unlit roads are often rural and faster; the share says how often these crashes kill, not how many people ride there.
The share is within crashes: with no counts of how many people walk, ride or drive where, it can't say how likely a crash is for anyone.
How it was found
A scan of the crash records found it in the earlier years, among thousands of patterns tested with a false-discovery control, and it held in the later years, which the scan never saw. A person then read it and checked it isn't an artefact of how crashes are recorded. The numbers above are recomputed from the data each time the site is rebuilt. All findings and the method
Where to look next
- Rear-end crashes are a small share of bike crashes but about five times as often fatal
- People hit on foot in the dark with no street lights are killed about four times as often
- A crash with a person on foot on a freeway kills them more than a third of the time
- On roads posted 50 mph or more, a third of pedestrian crashes are fatal