When a motorcycle goes down and no other vehicle touches it, the police report may label it a solo crash and the insurer may treat it as rider error. Often something else caused it: a pothole or an unmarked pavement edge, gravel or a ladder that fell off a truck, a car that drifted into your lane and kept going, or a tire or brake that failed. Each of those can support a claim, but each has its own rules, and some deadlines are measured in hours and months, not years.
Road Defects: A Government Claim on a Six-Month Clock
If a city, a county, or the state owns the road, Government Code section 835 can make the public entity liable for injuries caused by a dangerous condition of its property when the condition created a foreseeable risk of the kind of injury that happened, and either a public employee’s negligence created it or the entity knew or should have known about it in time to repair it or at least warn of it. Separate immunity statutes can still apply. On a motorcycle, conditions a car barely notices matter: a pothole in the tire’s path, a raised seam or pavement edge along the lane, a steel plate, or loose gravel from roadwork.
The deadline is the trap. Government Code section 911.2 requires a written claim to the public entity within six months of the crash. If the claim is rejected in writing, the lawsuit generally must be filed within six months of that notice under Government Code section 945.6. A private contractor that left the hazard is subject to the ordinary two-year deadline, but the agency that owns the road still needs its six-month claim.
Debris and Spilled Loads
A vehicle may not be driven on a highway unless it is built, covered, or loaded to keep its load from dropping, sifting, leaking, blowing, or spilling (Vehicle Code section 23114). Loads of gravel, sand, dirt, and similar aggregate material generally must also be covered. Vehicle Code section 23112 prohibits throwing or depositing anything on a highway that is likely to injure or damage traffic.
The driver and owner of the vehicle the load fell from can be responsible, and possibly the business that loaded it. The hard part is identifying them. Witnesses, dashcam footage, nearby business cameras, and the debris itself (packaging, a company name on lumber or equipment, a trail of material that ends at a job site) are how that vehicle gets found. If it is never identified, any uninsured motorist coverage you carry runs into the physical contact rule below, and the answer depends on the facts.
A Driver Forced You Off the Road Without Touching You
This is the familiar solo crash that is not really solo: a car drifts into your lane or pulls out in front of you, you brake hard or swerve, and you go down without contact.
If the driver is identified, the lack of contact does not prevent a claim. The question is whether that driver’s conduct caused your crash, and the claim goes to the driver’s liability insurer.
If the driver left and cannot be identified, the rules are strict. Under Insurance Code section 11580.2(b), uninsured motorist coverage for an unknown driver requires that:
- the injury arose out of physical contact between the unknown vehicle and you or the vehicle you were riding;
- the crash was reported within 24 hours to the city police department or, in unincorporated areas, to the county sheriff or the local CHP office; and
- you filed with your insurer, within 30 days after that, a statement under oath that you have a claim against a person whose identity cannot be determined, with the supporting facts.
So an unknown driver who never touched you generally leaves no uninsured motorist claim under the statute. That is why a witness who catches a plate number is so valuable: the physical contact requirement applies only when the driver is unknown. An identified driver with no insurance is an ordinary uninsured motorist claim, if your policy still carries that coverage (it can be waived in writing).
These claims have their own deadline. Within two years of the crash you must file suit against the uninsured driver, agree with your insurer on the amount owed, or formally start arbitration by written notice to the insurer sent by certified mail, return receipt requested (Insurance Code section 11580.2(i)).
Tires, Brakes, and Parts That Fail
A tread separation, a sudden loss of air, a brake that faded or locked, a stuck throttle, or a cracked wheel can put a rider down in a way that looks like rider error. If the part was defective, the manufacturer, the distributor, and the seller can be strictly responsible under California product liability law. A shop that recently mounted the tires or serviced the brakes owes ordinary care under Civil Code section 1714(a), and careless work can make it responsible.
These claims depend on the motorcycle itself, so keep it:
- Do not repair it, part it out, or let it be sold. If your insurer declares it a total loss, ask the insurer in writing to hold the motorcycle instead of sending it to auction.
- Keep the failed tire, wheel, and any parts removed at the scene or by the tow yard.
- Do not take it apart. Any inspection should happen with notice to the companies that may be responsible, so no one can later claim it was altered.
- Check nhtsa.gov for motorcycle and tire recalls, and gather service and purchase records for the parts in question.
The Helmet Law and Head Injury Damages
Vehicle Code section 27803 requires every motorcycle rider and passenger to wear a safety helmet meeting the requirements set under Vehicle Code section 27802, which include Federal Motor Vehicle Safety Standard No. 218. Wearing it means on the head, fastened with the straps, and sized to fit securely without excessive movement.
If you were not wearing a compliant helmet, or the strap was undone, expect the insurer to argue that your own fault should reduce the damages for a head injury. That argument is about causation. It should be limited to the injuries a compliant helmet would have prevented or lessened, not a broken leg, a shoulder injury, or road rash, and in court the defense has to prove it. Keep the helmet you were wearing, labels and all; the damage to it can help show where and how hard your head hit. Our page on brain injuries covers head trauma claims.
Evidence to Gather
- The scene: the road surface, gravel or debris, the pothole or seam with a tape measure for scale, skid and scrape marks, and the approach from your direction of travel.
- Witnesses and video: names and numbers, dashcams, your own helmet camera, and business or home cameras along the road. Footage is often overwritten within days.
- The report: Vehicle Code section 20008 requires the driver in any crash that injures someone to make a written report to the CHP or the city police within 24 hours. Make sure a report exists and get its number.
- The motorcycle, helmet, and riding gear, unrepaired and uncleaned.
- Medical records from the first visit on.
What to Do This Week
- Write down exactly what made you go down: the car, the debris, the pavement, or the part.
- If a driver forced you off and left, report it to the police right away if you have not, and notify your insurer in writing (a sworn statement within 30 days if it touched you or the motorcycle).
- Within 10 days, file the DMV’s SR-1 accident report (Vehicle Code section 16000).
- If a road defect played a part, count six months from the crash and calendar the claim date.
- Hold the motorcycle, the failed parts, and your helmet.
- Collect video and witness information before it disappears.
- Calendar two years from the crash, the general deadline for an injury lawsuit under Code of Civil Procedure section 335.1. More on motorcycle accident claims.
About the author. Joshua B. Adelpour is the founder of Not My Fault Law Group, APC, a California personal injury firm based in Woodland Hills. He is licensed by the State Bar of California, Bar No. 318226, and spent nearly a decade defending insurance companies in civil litigation before opening the firm. Call (213) 800-0706 for a free consultation.
This article is general information about California law and is not legal advice. Reading it does not create an attorney client relationship. Every case depends on its own facts. Last updated October 6, 2026.