Bike crashes on Commonwealth Ave, Fullerton

We don't rate streets as safe or unsafe: crash counts can't say how risky a street is, and busy streets have more crashes partly because more people use them. This page covers traffic crashes, not crime. What the records show: 18 bike crashes were reported on Commonwealth Ave in Fullerton from 2021–2026, 0 of them serious or fatal. The most were at Commonwealth Ave & Lemon St (3). 67% were side-impact crashes at junctions (drivers pulling out or turning across). 11% were riders hit from behind.

• The worst spot, on the mapCommonwealth Ave & Lemon St3 crashes. Side-impact crashes at the junction.
• Next in FullertonOrangethorpe Ave15 bike crashes, 2021–2026
• The whole cityBike hotspots in Fullerton188 bike crashes, 2021–2026

• 67% were side-impact crashes at junctions (drivers pulling out or turning across).
• 11% were riders hit from behind.
• 22% happened after dark.

1. Commonwealth Ave & Lemon St

   3 crashes

   Side-impact crashes at the junction

   3 of 3 crashes were broadside: a vehicle hit at an angle, usually a driver pulling out of a side street or driveway, turning across, or running the signal. 67% happened after dark. Traffic is posted at about 40 mph.

   • Slow down approaching the junction, watch drivers' front wheels at side streets and driveways, and don't assume a driver waiting to turn has seen you.
   • Use a front and rear light, even on lit streets.
   • Traffic is fast here. A quieter parallel street is often worth the extra minutes.
   See it on the map

2. Commonwealth Ave & Princeton Ave

   3 crashes

   A mix of crash types

   Traffic is posted at about 40 mph.

   • No single crash pattern stands out here. Slow down, stay visible, and leave extra room.
   • Traffic is fast here. A quieter parallel street is often worth the extra minutes.
   See it on the map

3. Commonwealth Ave & Basque Ave

   3 crashes

   Riders hit from behind

   2 of 3 crashes were rear-end: hit from behind. Traffic is posted at about 40 mph.

   • Run a bright rear light day and night, and ride where drivers see you early rather than tucked into the gutter. A mirror or rear radar helps.
   • Traffic is fast here. A quieter parallel street is often worth the extra minutes.
   See it on the map

4. Commonwealth Ave & Euclid St

   3 crashes

   Side-impact crashes at the junction

   3 of 3 crashes were broadside: a vehicle hit at an angle, usually a driver pulling out of a side street or driveway, turning across, or running the signal. Traffic is posted at about 40 mph.

   • Slow down approaching the junction, watch drivers' front wheels at side streets and driveways, and don't assume a driver waiting to turn has seen you.
   • Traffic is fast here. A quieter parallel street is often worth the extra minutes.
   See it on the map

Spots with 3 or more reported crashes within about 250 m, worst first.

The busiest hour was 10 a.m..

Where on Commonwealth Ave do the most bike crashes happen?

Commonwealth Ave & Lemon St, with 3 reported bike crashes from 2021–2026. Next are Commonwealth Ave & Princeton Ave (3) and Commonwealth Ave & Basque Ave (3).

How do cyclists usually get hit on Commonwealth Ave?

67% were side-impact crashes at junctions (drivers pulling out or turning across). 11% were riders hit from behind. 22% happened after dark.

How many bike crashes happen on Commonwealth Ave each year?

Reported bike crashes on Commonwealth Ave in Fullerton: 2021: 3, 2022: 3, 2023: 4, 2024: 5, 2025: 2, 2026: 1. The latest year can rise as late reports come in.

Where does this data come from?

Police crash reports in the California Crash Reporting System (CCRS), published by the state on data.ca.gov, counted by the street each report names first. Only crashes reported with map coordinates are counted, so the real totals are higher.