Arizona Bicycle Helmet Laws: Do You Have to Wear a Helmet?
Arizona has no statewide bicycle helmet law at any age, although some cities, towns and counties require helmets for bicyclists under 18. An adult cycling without one breaks no state law, while for children under 18 the answer depends on where they are cycling.
After a collision, the other motorist’s insurance company may still ask whether you were wearing one.
Can I Cycling Without a Helmet in Arizona?
In Arizona, you do not have to wear one to cycling unless a local ordinance applies to you, because no state statute requires one on a bicycle at any age.
The state’s motorcycle helmet law requires a helmet for operators and passengers under 18 on motorcycles, all-terrain vehicles and motor-driven cycles, but not on pedal bicycles. E-bikes have their own class rules in Arizona law, listed on the state’s e-bike laws page.
How a Missing Helmet Affects an Injury Claim
Cycling without one does not, by itself, stop you from recovering compensation, because the state’s pure comparative negligence law only reduces damages by your share of fault. However, the insurer may try to pay you less, treating that choice as your share of fault.
That position rests on two 1988 cases, Law v. Superior Court for seat belts and Warfel v. Cheney for motorcycle helmets. Because no published appellate decision has applied them to bicycle helmets, they reach bicycles only by analogy. Those cases also limit how far that argument can go:
- A jury may treat not wearing one as fault, even though no traffic law makes an adult wear one, but only if it finds the choice unreasonable.
- The reduction can reach only the part of a head trauma that helmets would have prevented or lessened, and has no bearing on who caused the crash.
- The defense has to prove that the missing helmets caused or worsened the head trauma and, with reasonable probability, by how much. In Warfel, a doctor’s testimony that the harm “would not have been as severe” with helmets was too vague to support any reduction.
If a jury values a head trauma at $60,000 and a broken wrist at $40,000, that argument reaches only the share of the $60,000 the jury finds helmets would have prevented or lessened.
Is It Illegal to Cycling Without a Helmet Under 18?
Cycling without one is illegal for children under 18 only where the city, town or county has an ordinance requiring one. Local ordinances for minors include these six:
- Tucson requires a properly fitted and fastened helmet for anyone under 18.
- Pima County has the same rule for its unincorporated areas.
- Sierra Vista has the same rule.
- Oro Valley has a rule on helmets for cyclists under 18.
- Flagstaff’s rule extends to e-bikes, scooters and skateboards.
- Tempe’s rule includes electric bicycles, their passengers and similar devices.
Each ordinance has force only inside its own city, town or county, which is why the rule can change at a city line.
What Happens If a Child Without One
For a minor in Tucson, unincorporated Pima County or Sierra Vista, cycling without one is a civil infraction with a $50 minimum fine. That fine can be waived on proof that the child has since obtained a qualifying one and will wear it.
Phoenix and East Valley Rules
The Phoenix police guide to e-bikes, e-scooters and motor-driven bicycles lists one rule on helmets, the state law for minors on motorcycles and motor-driven bicycles. Chandler and Gilbert now require helmets for anyone under 18 on an e-bike, as Tempe does. Because the rule follows the place, the code to check first is the local one, along with the statewide Arizona bicycle laws.
Why Wear a Bike Helmet When Arizona Does Not Require One
A bike helmet is worth wearing even where it is optional, because it is built to reduce serious injury, including traumatic brain damage.
Only 36.5% of the injured cyclists treated at Arizona trauma centers in 2021 were wearing helmets, according to the Arizona Department of Health Services trauma registry report. In its 2024 Crash Facts, the Arizona Department of Transportation (ADOT) reports 1,379 bicycle crashes statewide, with 1,349 bicyclists injured and 44 killed. The car and bicycle statistics page compares those counts with national figures.
Every new bike helmet sold in the United States must have a label showing it meets the federal CPSC safety standard. That protection depends on fit, with the helmet level above the brows and the chin strap buckled.
Talk to an Arizona Bicycle Accident Lawyer After a Crash
If the driver’s insurer asks whether you wore one, that is the time to have your case reviewed, whatever the answer. Attorneys at Bicycle Accident Lawyers Group are cyclists and injury lawyers who handle only bicycle accident cases.
If you’re a cyclist who has been in an accident, call today for a free initial consult about your legal claim. We’re here to help with your legal questions. Contact our law firm for coast-to-coast bike accident and personal injury representation.
Robert Goldwater is a cyclist representing cyclists. He has practiced personal injury and wrongful death law for more than 20 years, graduating with Honors from Arizona State University Law School, and has helped recover over $1 billion for clients, including injured cyclists.
