Where motorcycle crashes happen
Bends, straights and junctions
53% of these crashes involved no other vehicle, and those happen most in bends. Crashes with another vehicle happen most at junctions: 62% of them were within 40 m of one.
| Crash | In a bend | On a straight | At a junction |
|---|---|---|---|
| No other vehicle6,344 crashes | 40%2,520 crashes, 112 fatalRunning wide or losing grip: entry speed, line, the surface mid-corner. | 34%2,177 crashes, 145 fatalSpeed, animals, the road surface, late at night. | 26%1,647 crashes, 79 fatalBraking or swerving for a turning car without touching it, or gravel spilled at the junction. |
| With another vehicle5,599 crashes | 12%684 crashes, 67 fatalAn oncoming car over the centre line, or a blind overtake. | 25%1,425 crashes, 156 fatalFollowing, overtaking, or a car pulling out of a driveway. | 62%3,490 crashes, 268 fatalA driver turning across the rider or pulling out. |
Bend: the road curves tighter than a 100 m radius within 75 m of the crash. Junction: another road meets it within 40 m. Shares are of each row.
Downhill
CHP reports give the rider's direction, and the road's rise or fall there comes from USGS elevation, so each crash on a grade of 3% or more can be put going up or going down. On one road both directions carry about the same traffic. 65% of crashes alone in a bend were going downhill. Crashes with another vehicle in a bend split about evenly (52% downhill): the other car can come from either direction, so that even split is the check that the method works.
| Crash | Going downhill | Going uphill | Share downhill |
|---|---|---|---|
| No other vehicle, in a bend | 763 | 411 | 65% |
| No other vehicle, on a straight | 272 | 193 | 58% |
| No other vehicle, at a junction | 138 | 82 | 63% |
| With another vehicle, in a bend | 173 | 158 | 52% |
| With another vehicle, on a straight | 125 | 102 | 55% |
| With another vehicle, at a junction | 113 | 94 | 55% |
Crashes outside city limits with a known direction of travel, not on a bridge or in a tunnel; grade over 100 m either side of the crash.
Which bends
Every bend on the riding roads, compared with the other bends on the same road: its crashes against what its length would give at that road's average. The tighter the bend, the more crashes for its length. A bend much tighter than the bends either side of it had more again, and that holds for bends of the same radius: what stands out is a bend sharper than the ones around it. A long straight leading in made no clear difference. These are counts of reported crashes, not a rating of any one bend.
| Bend | Bends | Crashes | Against the road's average |
|---|---|---|---|
| Tightest radius | |||
| 60–100 m | 5,357 | 525 | 0.67× (0.61–0.72) |
| 30–60 m | 2,939 | 511 | 1.52× (1.39–1.66) |
| under 30 m | 853 | 162 | 2.20× (1.88–2.57) |
| Straight leading in | |||
| under 500 m | 7,984 | 968 | 1.00× (0.94–1.07) |
| 500 m or more | 1,165 | 230 | 0.98× (0.86–1.12) |
| Next to gentler bends | |||
| similar to its neighbours | 8,597 | 1,014 | 0.90× (0.84–0.95) |
| much tighter than its neighbours | 552 | 184 | 2.78× (2.39–3.21) |
| Same radius, next to gentler bends or not | |||
| 60–100 m, similar to its neighbours | 5,357 | 525 | 0.67× (0.61–0.72) |
| 30–60 m, similar to its neighbours | 2,696 | 415 | 1.37× (1.24–1.51) |
| 30–60 m, much tighter than its neighbours | 243 | 96 | 2.89× (2.34–3.53) |
| under 30 m, similar to its neighbours | 544 | 74 | 1.83× (1.43–2.29) |
| under 30 m, much tighter than its neighbours | 309 | 88 | 2.66× (2.13–3.28) |
In brackets: the 95% range (Poisson). Coloured where the whole range is above 1. “Much tighter”: a radius under 60% of the tighter neighbouring bend's. Bends with 3 or more crashes are on the motorcycling map.
The bends with the most crashes
Single bends outside city limits with the most reported motorcycle crashes. A count, not a rating: these are on roads many people ride. Each opens the map on the bend.
- 115 crashes in one bend on Highway 76 (SR-76)14 with no other vehicle · 15 of 15 on the grade going downhill · tightest radius about 42 m · 2021–2025
- 214 crashes in one bend on Angeles Forest Highway14 with no other vehicle · 1 of 1 on the grade going downhill · tightest radius about 80 m · 2021–2025 · road page
- 314 crashes in one bend on Highway 79 (Descanso to Julian)6 with no other vehicle · 14 of 14 on the grade going downhill · tightest radius about 44 m · 2021–2025 · road page
- 412 crashes in one bend on Highway 79 (Descanso to Julian)10 with no other vehicle · 11 of 11 on the grade going downhill · tightest radius about 73 m · 2021–2025 · road page
- 511 crashes in one bend on San Gabriel Canyon Road (SR-39)11 with no other vehicle · 11 of 11 on the grade going downhill · tightest radius about 29 m · 2021–2025 · road page
- 611 crashes in one bend on San Gabriel Canyon Road (SR-39)10 with no other vehicle · 7 of 11 on the grade going downhill · tightest radius about 37 m · 2021–2025 · road page
- 711 crashes in one bend on Route 78 (SR-78)5 with no other vehicle · 11 of 11 on the grade going downhill · tightest radius about 55 m · 2021–2025
- 810 crashes in one bend on Ortega Highway (SR-74)10 with no other vehicle · 2 of 10 on the grade going downhill · tightest radius about 66 m · 2021–2025 · road page
- 98 crashes in one bend on San Gabriel Canyon Road (SR-39)3 with no other vehicle · 2 of 8 on the grade going downhill · tightest radius about 26 m · 2021–2025 · road page
- 108 crashes in one bend on Campo Road (SR-94)3 with no other vehicle · 2 of 8 on the grade going downhill · tightest radius about 29 m · 2021–2025 · road page
Freeways
19,268 motorcycle crashes were reported on freeways, inside city limits and out. 76% involved another vehicle, against 60% on other roads, and 90% of those were sideswipes or rear-ends: vehicles going the same way. On other roads the most common is a broadside (43%), a car crossing or turning. Freeways have almost none of what causes crashes alone (tight bends, junctions, driveways), so what's left is mostly traffic.
They follow the commute: 50% were on a weekday between 6 and 9 am or 3 and 7 pm, against 34% on other roads. They are less often deadly: 3.0% were fatal, against 7.6% elsewhere, since vehicles going the same way hit at a smaller speed difference. More crashes on freeways also reflects how much of the driving they carry; it says nothing about a mile of freeway against a mile of other road.
California's Vehicle Code section 21658.1, added by AB 51 (2016), defines lane splitting as driving a two-wheeled motorcycle “between rows of stopped or moving vehicles in the same lane” and lets the CHP write educational guidelines for it. Crash reports don't record whether the rider was splitting, so these numbers can't say how many of these crashes happened that way.
Riding roads: crashes in bends vs the road's bends
On one road the same riders pass its bends and its straights, so this comparison needs no traffic counts. Where the share of crashes in bends is well above the share of the road that bends, crashes gather in the corners. Crashes away from junctions only; roads with fewer than 15 such crashes are left out.
Crashes: outside city limits, 2021–2025. In bends: of the crashes away from junctions. Coloured where the gap is more than chance would give (binomial test, p < 0.05).
Most crashes with no other vehicle
Stretches of road outside city limits with the most reported solo motorcycle crashes. These are mostly roads people ride for fun, so they lead partly because more riders use them: a count, not a ranking of risk.
- 1Angeles Crest Highway (SR-2)104 with no other vehicle (88% in bends) · 134 motorcycle crashes in all, 13 fatal · road page
- 2San Gabriel Canyon Road (SR-39)98 with no other vehicle (94% in bends) · 130 motorcycle crashes in all, 6 fatal · road page
- 3Angeles Forest Highway80 with no other vehicle (91% in bends) · 98 motorcycle crashes in all, 5 fatal · road page
- 4Highway 79 (Descanso to Julian)80 with no other vehicle (71% in bends) · 110 motorcycle crashes in all, 5 fatal · road page
- 5Highway 9 (Saratoga to Santa Cruz)68 with no other vehicle (81% in bends) · 121 motorcycle crashes in all, 3 fatal · road page
- 6Ortega Highway (SR-74)59 with no other vehicle (73% in bends) · 97 motorcycle crashes in all, 18 fatal · road page
- 7Campo Road (SR-94)57 with no other vehicle (61% in bends) · 114 motorcycle crashes in all, 9 fatal · road page
- 8Pines to Palms Highway (SR-74)53 with no other vehicle (75% in bends) · 81 motorcycle crashes in all, 1 fatal · road page
- 9Rim of the World Highway (SR-18) near San Bernardino44 with no other vehicle (20% in bends) · 54 motorcycle crashes in all, 2 fatal
- 10Highway 168 to Huntington Lake40 with no other vehicle (50% in bends) · 54 motorcycle crashes in all, 5 fatal · road page
- 11Highway 84, Woodside to La Honda35 with no other vehicle (91% in bends) · 55 motorcycle crashes in all, 2 fatal · road page
- 12Monticello Road (SR-121) near Napa31 with no other vehicle (77% in bends) · 38 motorcycle crashes in all, 1 fatal
- 13Highway 76 (SR-76) near Escondido31 with no other vehicle (81% in bends) · 34 motorcycle crashes in all, 1 fatal
- 14Highway 33 (Ojai to Cuyama)29 with no other vehicle (59% in bends) · 47 motorcycle crashes in all, 3 fatal · road page
- 15Pala Road (SR-76) near Temecula29 with no other vehicle (31% in bends) · 62 motorcycle crashes in all, 3 fatal
Most crashes with another vehicle
Stretches with the most reported crashes between a motorcycle and another vehicle. Busy roads lead here because they carry more traffic.
- 1Campo Road (SR-94)57 with another vehicle (44% at junctions) · 114 motorcycle crashes in all, 9 fatal · road page
- 2Highway 9 (Saratoga to Santa Cruz)53 with another vehicle (34% at junctions) · 121 motorcycle crashes in all, 3 fatal · road page
- 3Watt Avenue near Sacramento46 with another vehicle (89% at junctions) · 55 motorcycle crashes in all, 2 fatal
- 4Madison Avenue near Citrus Heights40 with another vehicle (93% at junctions) · 51 motorcycle crashes in all, 1 fatal
- 5Ortega Highway (SR-74)38 with another vehicle (37% at junctions) · 97 motorcycle crashes in all, 18 fatal · road page
- 6Pala Road (SR-76) near Temecula33 with another vehicle (45% at junctions) · 62 motorcycle crashes in all, 3 fatal
- 7San Gabriel Canyon Road (SR-39)32 with another vehicle (6% at junctions) · 130 motorcycle crashes in all, 6 fatal · road page
- 8Santa Cruz Highway (SR-17) near Los Gatos32 with another vehicle (31% at junctions) · 49 motorcycle crashes in all, 0 fatal
- 9Highway 79 (Descanso to Julian)30 with another vehicle (20% at junctions) · 110 motorcycle crashes in all, 5 fatal · road page
- 10Angeles Crest Highway (SR-2)30 with another vehicle (7% at junctions) · 134 motorcycle crashes in all, 13 fatal · road page
- 11Julian Road (SR-78) near San Diego30 with another vehicle (50% at junctions) · 53 motorcycle crashes in all, 4 fatal
- 12Pines to Palms Highway (SR-74)28 with another vehicle (39% at junctions) · 81 motorcycle crashes in all, 1 fatal · road page
- 13Elkhorn Boulevard near Sacramento28 with another vehicle (79% at junctions) · 31 motorcycle crashes in all, 1 fatal
- 14East Mission Road near Temecula25 with another vehicle (76% at junctions) · 36 motorcycle crashes in all, 2 fatal
- 15Mulholland Highway (incl. "The Snake")24 with another vehicle (38% at junctions) · 44 motorcycle crashes in all, 3 fatal · road page
Common questions
- Where do most motorcycle crashes happen in California?
- Outside city limits, where the CHP takes most reports and nearly all have a map location, 11,943 motorcycle crashes were reported on roads other than freeways from 2021–2025: 43% within 40 m of a junction, 27% in bends and 30% on straights. Inside cities most police reports have no map location, so they can't be placed on the road this way.
- Do most motorcycle crashes involve another vehicle?
- Outside city limits, 6,344 of 11,943 (53%) involved no other vehicle. Those happen most in bends (40%), while crashes with another vehicle happen most at junctions (62%).
- Which roads have the most motorcycle crashes?
- Counting crashes with no other vehicle, outside city limits: Angeles Crest Highway (SR-2) (104), San Gabriel Canyon Road (SR-39) (98), Angeles Forest Highway (80). These are roads many people ride for fun, so they have more crashes partly because more riders use them; the counts don't say how risky a road is. On Angeles Crest Highway (SR-2), 88% of them were in bends.
- Why do freeways have so many crashes with another vehicle?
- 76% of motorcycle crashes on freeways involved another vehicle, against 60% on other roads, and most were sideswipes or rear-ends in commute traffic (50% on weekday mornings and evenings). Freeways have few of the bends and junctions behind crashes alone, and they carry a lot of traffic.
- Are motorcycle crashes more likely going downhill?
- Alone in a bend, yes by count: 763 such crashes outside city limits were going downhill and 411 uphill, on roads where both directions carry about the same traffic. Crashes with another vehicle split about evenly.
- Why not rank the most dangerous roads?
- Risk needs to know how many riders use a road, and nobody counts motorcycles road by road. Without that, the busiest and best-loved roads always come out on top. What we can compare fairly is where on one road crashes happen: the same riders pass its bends and its straights.
- Where does this data come from?
- Crash reports from the California Crash Reporting System (CCRS) on data.ca.gov, 2021–2025, with a motorcycle involved and a map location, filed outside city limits. Each was placed on the nearest road in OpenStreetMap within 40 m; road bends are measured from OpenStreetMap's road lines.
Crashes: California Crash Reporting System (CCRS), 2021–2025, motorcycle crashes with map coordinates filed outside city limits, on roads other than freeways. Roads and bends: OpenStreetMap. A stretch is one road's crashes no more than 5 km apart. How the data works.