California Lane Splitting Law: CVC 21658.1 Explained
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This page was written and reviewed by Michael J. Cefali, Esq. Attorney Cefali is a founding partner of Cefali & Cefali, APC, based in San Juan Capistrano, CA. He holds a Juris Doctor from Chapman University Fowler School of Law and a B.A. in Global Studies & Maritime Affairs from the California Maritime Academy. Widely recognized for his advocacy in personal injury law, he has secured multi-hundred-thousand-dollar settlements in motorcycle accidents, hit-and-runs, and red-light collision cases. He maintains a perfect 10.0 “Superb” rating on Avvo.
Beyond his legal practice, Mr. Cefali actively supports his community through the Rotary Club of San Juan Capistrano, contributes to housing and meal programs for those in need, and enjoys fishing and spending time with his rescue dogs.
The date below reflects when this page was last reviewed for accuracy. Please see our Editorial Guidelines.
California Lane Splitting Law: CVC 21658.1 Explained
Yes, lane splitting is legal in California. California is the only U.S. state where motorcyclists can lawfully ride between rows of moving vehicles at any speed. The law is set by California Vehicle Code section 21658.1, which took effect January 1, 2017 after Assembly Bill 51 was signed the year before. The statute defines lane splitting and gives the California Highway Patrol authority to publish safety guidelines. It does not set a specific speed limit or speed-differential cap. Riders who split lanes still owe a duty of ordinary care, and unsafe lane splitting can trigger citations under other statutes like the Basic Speed Law. If you were injured in a lane splitting motorcycle accident, you still have the right to recover for your injuries under California's pure comparative negligence rule.
If you were hurt in a California lane splitting crash, call Cefali & Cefali at (949) 325-7790 for a free consultation. Available 24/7. No fee unless we recover for you.
Is Lane Splitting Legal in California?
Yes. Under California Vehicle Code section 21658.1, lane splitting is expressly permitted in California. The law took effect on January 1, 2017 when Assembly Bill 51, which had been signed by Governor Brown in August 2016, added the section to the Vehicle Code. California is currently the only state that permits motorcyclists to ride between rows of moving vehicles. A handful of other states (Utah, Arizona, Montana, and others) have since legalized a narrower practice called lane filtering, which typically applies only to stopped or very slowly moving traffic.
Being legal is not the same as being consequence-free. A motorcyclist who splits lanes recklessly can still be cited under other traffic statutes, and a rider who is injured while lane splitting may face insurance companies eager to shift some or all of the fault to them. Understanding what the statute actually says (and does not say) is the first step to protecting your rights.
What CVC 21658.1 Actually Says
The statute is short. It does two things: it defines lane splitting, and it authorizes CHP to publish safety guidelines.
Definition (subsection 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.
CHP authority (subsection b): The Department of the California Highway Patrol may develop educational guidelines relating to lane splitting in a manner that would ensure the safety of the motorcyclist and the drivers and passengers of the surrounding vehicles.
Required consultation (subsection c): In developing guidelines, CHP must consult with the DMV, the Department of Transportation, the Office of Traffic Safety, and a motorcycle organization focused on motorcyclist safety.
Three things the statute does not do:
It does not set a speed limit for lane splitting
It does not set a speed-differential cap between the motorcycle and surrounding traffic
It does not create its own penalty. Officers who see unsafe lane splitting cite under other statutes
This is where a lot of online guides get the law wrong. There is no "must be under 30 mph" rule and no "must be within 10 mph of surrounding traffic" rule written into the statute. Those numbers appeared in earlier CHP guidance that has since been rescinded. The current CHP approach uses general principles rather than fixed thresholds.
How California Legalized Lane Splitting
Before 2017, lane splitting existed in a legal gray zone in California. It was not expressly authorized by statute, but it was not expressly prohibited either. Riders had been splitting lanes for decades, and CHP had, at times, published informal safety guidance. In 2013, CHP posted a set of guidelines that included specific speed thresholds (splitting at no more than 10 mph faster than surrounding traffic, and never above 30 mph total speed). Those guidelines were removed in 2014 after concerns about whether CHP had the authority to publish specific safety rules in the absence of a statute.
Assembly Bill 51, sponsored by Assembly Member Bill Quirk, was signed by Governor Jerry Brown in August 2016. It added section 21658.1 to the Vehicle Code effective January 1, 2017. The statute made three key changes:
It formally defined lane splitting for the first time in California law
It confirmed that lane splitting is a lawful maneuver
It authorized CHP to publish educational safety guidelines with input from other state agencies and motorcycle safety organizations
Since then, CHP has posted safety guidelines on its motorcyclist safety page. Those current guidelines are principle-based rather than number-based, focusing on general factors that increase or decrease risk.
Current CHP Safety Guidelines for Lane Splitting
The CHP's current guidelines, published as part of the California Motorcyclist Safety Program, focus on factors that affect the risk of lane splitting rather than fixed rules. The key principles:
Danger increases as speed differential increases. The greater the difference between your speed and surrounding traffic, the more difficult it becomes for other drivers to react to your presence.
Danger increases as overall speed increases. Lane splitting at low speeds in stopped or crawling traffic is much less dangerous than at higher freeway speeds.
Consider the total environment. Lane width, other vehicles' size, road conditions, weather, and visibility all matter.
Split between the far-left lanes when possible. These are typically safer than splitting between other lane pairs, both because of driver expectations and because of vehicle mix.
Avoid splitting near large vehicles. Buses, big rigs, motorhomes, and RVs have significant blind spots and can push a motorcycle sideways with turbulence.
Be visible. Brightly colored or reflective gear, high beams even during daylight, and staying out of blind spots all reduce risk.
Avoid lingering in blind spots. Do not ride alongside a vehicle for extended periods. Get past and clear the space.
These are educational guidelines, not regulatory rules. Violating them alone does not trigger a citation. But they matter for two reasons: they inform how a CHP officer or local officer will evaluate the reasonableness of your riding in a crash investigation, and they become a benchmark that insurance companies, defense lawyers, and juries use when deciding whether a lane-splitting rider was riding reasonably.
Lane Splitting vs. Lane Filtering vs. Lane Sharing
These terms are often used interchangeably, but they mean different things.
Lane splitting is riding between rows of vehicles that may be moving or stopped. This is what California uniquely allows under CVC 21658.1. Motorcyclists can pass between vehicles that are traveling at moderate freeway speeds, not just when traffic is stopped.
Lane filtering is a narrower practice: moving between vehicles only when traffic is stopped or barely moving, typically at a red light or in a slowly moving jam. Utah, Arizona, Montana, and a growing list of other states have legalized lane filtering under specific speed caps. California's law is broader because it covers both stopped and moving vehicles.
Lane sharing most often refers to two motorcycles riding side by side within a single lane, though the term is sometimes used loosely to mean either lane splitting or lane filtering. Two motorcycles sharing a single lane in California is generally permissible.
For clarity in a claim or lawsuit, use the precise term "lane splitting" as defined by CVC 21658.1 to describe the practice that California allows.
Driver Obligations Around Lane-Splitting Motorcyclists
Because lane splitting is legal, drivers of cars, trucks, and other vehicles have specific obligations toward motorcyclists who are splitting lanes. The CHP is clear on this:
It is illegal to intentionally block or impede a motorcyclist who is lane splitting in a way that could cause harm to the rider.
It is illegal to open a vehicle door to impede a motorcyclist. This includes both passenger doors and driver doors while a motorcyclist is passing.
Drivers in the far left lane are asked to move to the left of their lane to give motorcyclists room to pass safely on their right.
Drivers must check blind spots before changing lanes or making turns, particularly during heavy traffic when lane splitting is more common.
Drivers must signal before changing lanes, and lane changes must be reasonably safe under CVC 22107.
A driver who intentionally blocks a motorcyclist, opens a door in the path of a lane-splitting rider, or fails to check for motorcyclists before changing lanes bears significant legal responsibility for any resulting collision.
Can You Be Cited for Unsafe Lane Splitting?
Yes. CVC 21658.1 does not include its own penalty provision, but officers can and do cite motorcyclists who split lanes dangerously using other statutes. The most common:
CVC 22350, the Basic Speed Law. This prohibits driving at a speed greater than reasonable under the conditions. A motorcyclist splitting lanes at 60 mph past cars traveling at 20 mph in poor visibility can be cited under this section even if the posted limit is 65.
CVC 23103, reckless driving. A motorcyclist whose lane splitting shows willful or wanton disregard for the safety of persons or property can face a reckless driving charge. This is a misdemeanor with significant penalties and insurance consequences.
CVC 22107, unsafe lane change. A rider who changes lanes without safety can be cited even without an accident occurring.
Following-distance violations. Splitting between vehicles that are following each other too closely can result in a related citation.
A citation is not a conviction, and citations can be contested. But being cited under one of these statutes creates a formal record that insurance companies and defense lawyers will use in any subsequent injury case.
Fault and Liability in Lane Splitting Motorcycle Accidents
California follows pure comparative negligence, which shapes every lane splitting accident case. Under this rule, an injured party can recover damages reduced by their own percentage of fault, no matter how high. A rider found 30 percent at fault for a lane splitting crash can still recover 70 percent of the damages. Even a rider found 90 percent at fault can recover 10 percent.
Because lane splitting is legal, a rider is not automatically at fault for a crash that happens while splitting. However, insurance companies routinely try to assign fault to the motorcyclist based on the CHP safety guidelines. The insurer's arguments typically go like this:
The motorcyclist was traveling at too high a speed differential relative to surrounding traffic
The motorcyclist was splitting at unreasonably high overall speed
The motorcyclist was riding in poor conditions where lane splitting is discouraged
The motorcyclist was next to a large vehicle where lane splitting is more dangerous
The motorcyclist was not visible enough to other drivers
The motorcyclist's job is to reframe the analysis. The other driver's failure to check mirrors, signal before changing lanes, or maintain a safe following distance is often the actual cause of the crash. The CHP guidelines apply to both riders and drivers, and the driver's obligations toward lane-splitting motorcyclists are just as real as the rider's obligation to split safely.
Common Defense Arguments Against Lane-Splitting Motorcyclists
Insurance defense lawyers and adjusters have a familiar playbook for lane splitting crashes. Knowing the arguments in advance helps you counter them.
"The motorcyclist appeared out of nowhere." This is the single most common defense assertion. The counter is documentation: your speed, your visibility, your lane position, and whether the driver was paying attention. Photos of the scene, dashcam or motorcycle camera footage, and witness statements are the strongest tools.
"The motorcyclist was going too fast for the conditions." The counter is often the Basic Speed Law itself: the driver had an equal obligation to drive reasonably for the conditions and to look for motorcyclists before merging or changing lanes.
"Lane splitting caused the crash by itself." This is legally wrong. Lane splitting is legal. The question is not whether the rider was splitting, but whether the specific way the rider was splitting was reasonable, and whether the driver breached their own duty of care.
"The motorcyclist violated the CHP guidelines." The counter is that CHP guidelines are educational, not regulatory, and the driver's conduct still contributed to the crash. Even a rider who was splitting outside the CHP safety envelope can recover if the driver's actions were a substantial cause of the collision.
What to Do If You Were Hit While Lane Splitting
If you were injured in a lane splitting motorcycle accident, the steps in the first hour matter enormously. In order of priority:
Get medical attention. Motorcycle injuries frequently include internal or head injuries that are not immediately apparent. Delayed treatment is the first argument insurance companies use against your claim.
Call 911 and let CHP or local police respond. The police report is often the most important document in a lane splitting case.
Photograph the scene. Vehicle positions, damage locations, road markings, sightlines, traffic conditions, weather. Do this before vehicles are moved.
Get witness information. Independent witness testimony is often the single most important evidence in a disputed lane splitting case.
Preserve any dashcam or helmet camera footage. If you had a camera running, protect that footage immediately.
File the DMV SR-1 within 10 days. Required under California Vehicle Code section 16000 for any accident with injury, death, or damage over $1,000. See our SR-1 form guide.
Do not give a recorded statement to the other driver's insurance. Our guide on the first week after a car accident covers the specific traps.
Speak with a motorcycle accident attorney. Lane splitting cases are frequently disputed, and the strategic decisions made early determine whether you recover fairly or take pennies on the dollar.
Frequently Asked Questions About California Lane Splitting Law
Is lane splitting legal in California?
Yes. California Vehicle Code section 21658.1, which took effect January 1, 2017 after the signing of Assembly Bill 51, expressly permits lane splitting on divided and undivided streets, roads, and highways. California is currently the only U.S. state that permits motorcyclists to ride between rows of moving vehicles.
Is there a speed limit for lane splitting in California?
The statute does not set a specific speed limit or speed-differential cap for lane splitting. The current CHP safety guidelines are principle-based rather than number-based. Earlier CHP guidance included specific numbers (10 mph differential, 30 mph maximum) but those were rescinded before AB 51 was signed. All standard speed laws still apply, including the Basic Speed Law under CVC 22350.
What is the difference between lane splitting and lane filtering?
Lane splitting is riding between rows of moving or stopped vehicles, which is what California uniquely permits. Lane filtering is a narrower practice: moving between vehicles only when traffic is stopped or nearly stopped, typically at a red light or in a slow jam. Some other states (Utah, Arizona, Montana) permit lane filtering but not lane splitting at higher speeds.
Can I get a ticket for lane splitting in California?
CVC 21658.1 itself does not create a lane splitting citation. However, unsafe lane splitting can trigger citations under other statutes: the Basic Speed Law (CVC 22350), reckless driving (CVC 23103), unsafe lane change (CVC 22107), or following too closely. Lane splitting itself is not illegal.
Can a driver block a motorcyclist who is lane splitting?
No. It is illegal to intentionally block or impede a motorcyclist who is lane splitting in a way that could cause harm. It is also illegal to open a vehicle door to impede a lane-splitting motorcyclist. Drivers who violate these rules can face citations and bear significant civil liability if their actions cause a crash.
Am I automatically at fault if I was lane splitting when I was hit?
No. Because lane splitting is legal, a motorcyclist is not automatically at fault for a crash while splitting. California follows pure comparative negligence, meaning fault is apportioned based on the specific conduct of each party. Even if a jury assigns some percentage of fault to the rider, the rider can still recover damages reduced by that percentage.
Do CHP safety guidelines have the force of law?
The CHP safety guidelines are educational, not regulatory. Violating them alone does not trigger a citation. However, the guidelines matter in practice because insurance companies, defense lawyers, and juries use them as a benchmark for reasonable riding when a crash happens.
When did lane splitting become legal in California?
Assembly Bill 51 was signed by Governor Jerry Brown in August 2016. California Vehicle Code section 21658.1 took effect January 1, 2017. Before this, lane splitting existed in a legal gray zone: not expressly permitted, but not expressly prohibited either.
Is lane splitting legal on California surface streets, or only freeways?
Both. CVC 21658.1 specifies that lane splitting is permitted on both divided and undivided streets, roads, and highways. There is no freeway-only limitation.
Can I be reported by another driver for lane splitting?
A driver can call in an unsafe motorcyclist, but lane splitting itself is not illegal, so a driver report does not create a citation on its own. If an officer responds and observes unsafe conduct, a citation can be issued under one of the general traffic statutes.
What insurance covers me if I was hit while lane splitting?
Standard California auto insurance applies to lane splitting motorcycle accidents. If the at-fault driver has insurance, you file a bodily injury claim against their liability coverage. If the at-fault driver is uninsured or fled the scene, your own uninsured motorist (UM) coverage typically applies. See our insurance after a car accident guide for details.
Should I hire an attorney for a lane splitting motorcycle accident?
Lane splitting cases are disputed more often than other motorcycle claims because insurers routinely try to blame the rider. Represented motorcycle claimants consistently recover more than unrepresented claimants in similar fact patterns. If you were hurt in a lane splitting crash, a consultation with an experienced motorcycle accident attorney is worth having.
Talk to a California Motorcycle Accident Attorney
If you were injured in a California lane splitting crash, Cefali & Cefali offers a free case evaluation to explain your rights and the recovery paths available to you. We handle every stage of the case on contingency, from evidence preservation and CHP report review through insurance negotiation and, when needed, litigation.
Michael Cefali is a dedicated accident attorney based in San Juan Capistrano, California, committed to securing justice and fair compensation for accident victims.
A graduate of Newport Harbor High School, he went on to earn his Bachelor’s degree in Global Studies and Maritime Affairs from the California Maritime Academy, followed by his Juris Doctor from Chapman University School of Law.
Deeply invested in his community, Michael is an active member of the Rotary Club of San Juan Capistrano, contributing to efforts that provide meals, housing, and support to those in need. Outside of his legal work and volunteer service, he enjoys fishing in Dana Point and spending time with his three rescue dogs—a Chihuahua, a Spaniel mix, and a Shepherd mix.
Driven by his strong belief in justice and fairness, Michael remains steadfast in advocating for individuals harmed by the negligence or inaction of others.
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