Lane splitting is legal in California, and doing it does not make a crash your fault. California was the first state to write it into law, in Vehicle Code section 21658.1, added by Assembly Bill 51 and effective 1 January 2017.
That matters because the first thing most riders hear after a collision, often from the other driver’s insurer, is that they should not have been between the lanes. In California that argument starts from a false premise.
This article is by Accident Lawyer of California, P.C., the personal injury practice of Aryan Aliakbarzadeh, Esq. in Northridge, California, admitted to the State Bar of California in October 2012. It describes how these cases work in California; it is not advice about yours.
What the statute actually says Link to this section
Section 21658.1 defines lane splitting as riding a two wheeled motorcycle between rows of stopped or moving vehicles in the same lane, on divided or undivided roads.
Then it does something people find surprising. It sets no speed limit for lane splitting, and no cap on how much faster you may be traveling than the traffic around you. There is no number in the statute at all.
The CHP guidelines are not the law Link to this section
The same statute allows the California Highway Patrol to publish educational safety guidelines, developed with the DMV, Caltrans, the Office of Traffic Safety and a motorcycle safety organization.
Two things follow from that, and riders need both.
Those guidelines are educational, not regulatory. Riding outside them is not an offense on its own and does not produce a citation by itself.
But an insurer will still use them. Defense lawyers quote them, adjusters quote them, and a jury may treat them as a reasonable benchmark for how a careful rider behaves. So they have no force as law and real force as argument.
Earlier CHP guidance did contain specific numbers. Those were withdrawn before AB 51 was signed, and the current guidelines are principle based rather than numeric. If an adjuster quotes you a speed threshold as though it were a rule, ask them where it comes from.
So how is fault actually decided Link to this section
The same way it is in every other California collision. Fault is apportioned under pure comparative fault, which means each party carries the percentage of responsibility the evidence supports.
Legal conduct can still be done carelessly. Lane splitting at a sensible speed through slow traffic is one thing. Lane splitting at forty miles an hour past stationary cars is another, and the basic speed law in Vehicle Code section 22350 still applies to a motorcycle between the lanes. The question is never whether the maneuver was permitted. It is how it was carried out.
And it runs in both directions. A driver who changes lanes without a mirror check, or who opens a door into a splitting lane, or who deliberately blocks a rider, carries their share.
Being found partly at fault does not end the claim. It reduces the recovery by your percentage, and California has no cutoff where you lose the right to recover entirely.
The helmet question Link to this section
California requires a helmet for every rider and every passenger, under Vehicle Code section 27803. If you were not wearing one, expect the insurer to raise it.
Like the seat belt argument in a car case, it is relevant only to the injuries a helmet could have affected. An insurer that applies it to a broken leg is overreaching, and that is worth saying out loud rather than absorbing.
What makes these claims different Link to this section
A motorcycle accident claim is built from more physical evidence than a car claim, because there is less vehicle to tell the story and more rider.
Where the bike came to rest, and where you did, relative to the point of impact.
Scrape and gouge marks on the road surface, which fade within days.
Damage on the other vehicle, specifically its height and angle, which often shows whether it moved into you or you into it.
Helmet and gear damage, which is evidence and should not be thrown away however unpleasant it is to keep.
Traffic and business camera footage, which is the most perishable of all. Many systems overwrite within days or weeks.
Expect the other side to lean on an assumption that appears in no statute, which is that the rider was the reckless one. That assumption is beaten with evidence, and evidence disappears fastest in exactly the period when you are least able to go and collect it.
What to do this week Link to this section
Photograph the bike from every angle before anything is repaired or scrapped, and do not let the insurer dispose of it until it has been examined.
Keep the helmet and the gear, damaged, unwashed and exactly as they are.
Ask nearby businesses about camera footage now, this week.
See a doctor, including for the things you are dismissing as road rash, and keep going.
Say nothing about your speed, and give no recorded statement to the other driver’s insurer, until you understand what is actually being established.
If someone has told you that lane splitting means you have no claim, that is worth a second opinion before you accept it. The consultation costs nothing and the line is open 24 hours.