Yes. Lane splitting is legal in California, and since January 1, 2017, Vehicle Code § 21658.1 has defined it in state law. That statute sets no speed limit. It defines the practice and lets the California Highway Patrol (CHP) publish safety guidance.
Two claims repeated across the web are out of date. CHP does not cap lane splitting at 10 mph over traffic, and California is no longer the only state that lets riders move between lanes.
What Vehicle Code § 21658.1 Says
Under subdivision (a), lane splitting means “driving a motorcycle, as defined in Section 400, that has two wheels in contact with the ground, between rows of stopped or moving vehicles in the same lane, including on both divided and undivided streets, roads, or highways.”
Read it closely and a few limits show up:
- Two wheels only. A trike or a motorcycle with a sidecar does not fit the definition.
- Stopped or moving traffic. Riding up between cars stopped at a light counts, and so does riding between moving cars on a freeway.
- Streets as well as freeways. “Divided and undivided streets, roads, or highways” includes city streets, not just freeways.
The rest is about guidance. Subdivisions (b) and (c) let CHP write “educational guidelines” after consulting the DMV, Caltrans, the Office of Traffic Safety (OTS) and a motorcycle safety organization.
The section has no speed cap, no speed differential, no list of approved lanes and no penalty. Every other traffic law still applies, including these:
- The basic speed law (§ 22350). No one may drive “at a speed greater than is reasonable or prudent” given weather, visibility, traffic and the width of the road.
- Safe passing (§ 21750). A passing vehicle must pass “at a safe distance without interfering with the safe operation of the overtaken vehicle.”
- No passing off the pavement (§ 21755). Passing on the right can never be done “by driving off the paved or main-traveled portion of the roadway.” CHP says riding on the shoulder is illegal and is not lane splitting.
Why California’s Law Has No Speed Limit
California never banned lane splitting. When the Senate Transportation and Housing Committee analyzed the bill that became § 21658.1 in June 2016, it summed up the author’s view this way: “Because statute does not specifically prohibit lane splitting, it is allowed with no restrictions.”
Speed numbers came later, and briefly. In early 2013, CHP posted lane splitting guidelines that told riders to travel no more than 10 mph faster than other traffic and said it was “not advisable” to split when traffic moved at 30 mph or faster. An expanded version, “Lane Splitting General Guidelines,” defined being reasonable as “not more than 10 MPH faster than traffic flow and not over 39 MPH.”
Those guidelines did not last. According to the committee analysis, a complaint to the Office of Administrative Law argued they were “underground regulations” written without a public process. The office said CHP had no authority to publish them. CHP took them down, and the DMV and OTS followed.
The Legislature responded with Assembly Bill 51. The version that passed the Assembly in 2015 allowed lane splitting only at 50 mph or less and no more than 15 mph faster than traffic. Senate amendments on June 1, 2016 deleted both limits. The governor signed the bill on August 19, 2016, and it took effect January 1, 2017, with no numbers in it.
Websites that still present 10 mph or 30 mph as CHP rules are quoting guidance CHP withdrew before AB 51 passed.
What CHP Tells Riders and Drivers Today
CHP’s current lane splitting tips, on its California Motorcyclist Safety page, contain no speed figures. The disclaimer says lane splitting should not be done by inexperienced riders and that the risk of death or serious injury rises as speed and speed differential rise.
For riders, CHP advises:
- Consider lane width, the size of nearby vehicles, and road, weather and lighting conditions.
- Split between the far left lanes when you can. CHP says that is typically safer.
- Avoid splitting next to big rigs, buses and motorhomes.
- Don’t linger in blind spots or between vehicles.
- Wear brightly colored or reflective gear and use your high beam during the day.
For drivers, CHP says:
- Lane splitting by motorcyclists is legal in California.
- Intentionally blocking or impeding a motorcyclist in a way that could cause harm is illegal.
- Opening a vehicle door to impede a motorcyclist is illegal.
- Drivers in the far left lane should move to the left side of their lane to give riders room.
What the Crash Data Shows
California’s lane splitting crash data comes from a 2015 UC Berkeley study funded by NHTSA through an OTS grant. Researchers at the Safe Transportation Research and Education Center (SafeTREC) studied 5,969 motorcyclists involved in crashes on roads patrolled by CHP from June 2012 through August 2013. Of those, 997 (17%) were lane splitting.
Compared with other riders in crashes, the lane splitters:
- suffered head injuries less often (9% vs. 17%)
- suffered torso injuries less often (19% vs. 29%)
- were killed less often (1.2% vs. 3.0%)
- were rear-ended less often (2.6% vs. 4.6%)
- were more than twice as likely to have rear-ended another vehicle (38% vs. 16%)
Speed predicted the injuries. In lane splitting crashes, head injuries stayed low at motorcycle speeds up to 50 mph (6.6% on average) and rose sharply above that (16.7%). A speed gap of up to 15 mph over traffic was not linked to more injuries. Above 15 mph, each injury type grew more likely as the gap widened. The authors concluded lane splitting is relatively safe in traffic moving at 50 mph or less when riders go no more than 15 mph faster than the cars around them.
The authors call one limit primary. The study had no data on riders who split lanes without crashing, so it cannot say whether lane splitting raises or lowers your odds of a crash in the first place. It also recorded injuries only as yes or no, so a minor injury and a critical one counted the same.
A 2014 UC Berkeley survey described in the same report found that 36% of the California drivers surveyed wrongly believed lane splitting on multi-lane roads was illegal, and another 12% weren’t sure.
According to SafeTREC’s 2025 motorcycle safety fact sheet, 52 motorcyclists were killed and 317 were seriously injured in San Diego County in 2023, second only to Los Angeles County on both counts. The injury count comes from provisional state crash data. Those figures cover all motorcycle crashes, not only lane splitting. Statewide, unsafe speed was the most common primary factor in fatal and serious-injury motorcycle crashes that year, at 28.2%.
Who Is at Fault in a Lane Splitting Accident?
Fault in a lane splitting crash goes to whoever was careless, and that can be the rider, the driver or both. Splitting is legal, so no statute makes a rider negligent just for doing it. Legality also does not protect a rider who splits carelessly.
California uses comparative fault. CACI No. 405 is the standard jury instruction on an injured person’s own share of the blame. Under it, the other side has to prove two things: that you were negligent, and that your negligence was a substantial factor in causing your harm. If it proves both, the jury sets your percentage of responsibility and your damages drop by that share. A rider found partly at fault still recovers the rest.
Vehicle Code violations carry extra weight. Under CACI No. 418, if a party violated a statute and the violation was a substantial factor in causing the harm, the jury must find that party negligent unless the violation was excused. That cuts both ways in a lane splitting crash.
Arguments insurers raise against riders:
- Speed too fast for conditions under the basic speed law.
- Rear-ending a car that stopped or slowed. The Berkeley numbers show how common this is in lane splitting crashes.
- Riding on the shoulder, which is not lane splitting at all.
Arguments riders raise against drivers:
- Changing lanes without checking. Vehicle Code § 22107 bars moving right or left “until such movement can be made with reasonable safety” and requires a signal when another vehicle may be affected.
- Opening a door into the gap. Vehicle Code § 22517 bars opening a door on the traffic side “unless it is reasonably safe to do so.”
- Moving over on purpose to block or impede a rider, which CHP says is illegal.
CHP’s lane splitting tips are educational guidelines, not law, and they contain no speed number. Going faster than the old, withdrawn 10 mph figure is not a Vehicle Code violation on its own. An insurer can still argue that a big speed gap shows the rider broke the basic speed law.
These cases turn on evidence. Damage location, dashcam and helmet camera video, the collision report and witnesses usually show who moved into whose path. For more on lane-change fault in general, see who is at fault in a lane change accident. If you were hurt, our San Diego motorcycle accident lawyers page explains how these claims work locally.
Where Else Is Lane Splitting Legal?
California is no longer the only state, but no other state goes as far. Lane splitting means riding between lanes of moving traffic. Lane filtering means moving between stopped vehicles, usually up to the front at a light. As of October 2026, these states allow one or both by statute:
- Utah (filtering, since May 2019): only on roads with a speed limit of 45 mph or less (or a multi-lane off-ramp), only past stopped vehicles, and only at 15 mph or less. A Utah ban on lane splitting in moving traffic (§ 41-6a-704.1) took effect January 1, 2026, and the filtering law expires July 1, 2027 unless extended. Utah Code § 41-6a-704(6).
- Montana (filtering, 2021): riders may pass vehicles that are stopped or moving no faster than 10 mph, at no more than 20 mph. Mont. Code Ann. § 61-8-392.
- Arizona (filtering, signed March 2022): stopped vehicles only, on streets with a speed limit of 45 mph or less, at no more than 15 mph. A.R.S. § 28-903(F).
- Colorado (filtering, since August 7, 2024): stopped traffic only, at 15 mph or less, and never on the right shoulder. The authorization is set to repeal September 1, 2027 unless lawmakers extend it. SB24-079.
- Minnesota (splitting and filtering, since July 1, 2025): riders may pass within the same lane, in moving or stopped traffic, at no more than 25 mph and no more than 15 mph faster than traffic. Minn. Stat. § 169.974, subd. 5.
Every one of those laws writes a speed number into the statute. California’s does not. Splitting freeway traffic moving at highway speed is legal here and illegal in all five of those states.
Frequently Asked Questions
Is there a speed limit for lane splitting in California?
Not a separate one. Section 21658.1 sets no speed and no speed differential. The posted limit and the basic speed law still apply. The Berkeley study found injuries climbed once riders went more than 15 mph faster than traffic.
Can motorcycles filter to the front at a red light in California?
Yes. The definition covers riding “between rows of stopped or moving vehicles,” so moving up between cars stopped at a light is lane splitting under California law.
Is lane splitting legal on city streets or only on freeways?
Both. The statute covers “divided and undivided streets, roads, or highways.” The Berkeley study only looked at crashes on roads CHP patrols, and 94% of the lane splitting riders in it were on a state highway, so it says little about city streets.
Can a driver block a motorcycle that is lane splitting?
No. CHP says intentionally blocking or impeding a motorcyclist in a way that could cause harm is illegal, and so is opening a door to impede one. Section 21658.1 does not require drivers to make room, but CHP asks drivers in the far left lane to move to the left side of their lane.
Can I recover compensation if I was hit while lane splitting?
Yes, if someone else’s negligence was a substantial factor in causing the crash. Lane splitting does not bar a claim. Any share of fault proven against you reduces your recovery. It does not erase it.
Do I need a helmet to lane split?
Yes. Vehicle Code § 27803 requires every motorcycle driver and passenger to wear a safety helmet that meets state requirements, split or not. Our guide to San Diego motorcycle laws covers the details.
Hurt in a Lane Splitting Crash?
If you were injured in a lane splitting crash in San Diego County, call Gomez Trial Attorneys at (619) 237-3490 to talk through what happened.
