Adult Bicycle Helmet Laws In the US

Bicycle HelmetAdult bicycle helmet laws draw no end of passion on both sides. We don’t call them the “bicycle helmet wars” for nothing. But until recently I was under the mistaken belief that there were few – if any – jurisdictions in the United States that actually had laws regarding adult usage of bicycle helmets. This belief was shattered on a recent trip to Washington state where, coincidentally, two totally different people completely unconnected made comments about King County Washington having a helmet requirement for adults.

Me being Mr. Skeptical of course went to the one and only authority as soon as I got home – Google. I was admittedly surprised.

Washington State adult bicycle helmet laws

My search turned up a page on the Washington State Department of Transportation website listing jurisdictions in Washington state with bicycle helmet laws. There were two things that jumped out at me.

First, apparently Washington State has not state-wide law regarding bicycle helmets for either children or adults.

Second, there are a ton of counties and/or cities that do have adult bicycle helmet laws.

Third, of all the jurisdictions with laws, a surprisingly small number (2) are targeted exclusively at children, while the vast majority of them (33) target all ages

I started off assuming there were no laws anywhere in the United States regarding adults and bicycle helmet use. I found 33 examples – in one state alone – of where I was wrong.

Clearly I needed to do some more research.

Nation wide adult bicycle helmet laws

Child in cargo bike without helmetThere were actually not one but two assumptions I had made that were proving wrong. First, I assumed the majority of all states had laws regarding children’s bicycle helmet usage (For the duration of this article, I’ll lump all laws that require bicycle helmets for youth under any age from 12-18 as “children’s helmet laws.”) According to data compiled on the website, there are only 21 states with state-wide mandates for any age groups. Of those, the vast majority are for children aged 16 years and younger. California, Delaware and New Mexico require helmets for riders 18 or under. Massachusetts and New Jersey, 17 and under. West Virginia, New Work and Louisiana require them for ages 15, 14 and 12 respectively. I was correct that no state anywhere in the US has any laws on the books requiring adult bicycle helmet usage.

My shock at the number of adult bicycle helmet laws in place in cities and counties within Washington state – 33 – was easily explained however. It just so happens that Washington state has far more adult bicycle helmet laws than any other state. Again, according to all-ages helmet requirement data compiled by,  there are currently 67 laws on the books. Just to reiterate, 33 of those 67 are in Washington state. The next highest – Missouri – has only 14. All told, there are 15 states that contain jurisdictions with adult bicycle helmet laws on the books.

A note about

Photo by Richard Masoner / Cyclelicious
Photo by Richard Masoner / Cyclelicious

Some readers may be surprised to see me site data from The website is, after all, an advocacy group promoting the usage of bicycle helmets. has a history of being against bicycle helmet advocacy efforts, and questioning the common wisdom about what protection is actually provided. With that apparent contradiction admitted, is very clear about presenting data and encouraging folks to draw their own conclusions.

Our own belief, of course, is that a cyclist should wear a bike helmet. We are helmet advocates, after all.

In 2010 we saw an increase in blog posts from cyclists who do not believe you should wear a helmet. They challenged the conventional wisdom that helmets are necessary to reduce brain injures. That has continued now for the intervening years. The positive experience with shared bicycle programs has raised basic questions about the need for helmets, and some riders are reconsidering.

While I may not agree with their particular stance, I fully support their forthright presentation. Distinguishing data from beliefs is something increasingly rare. Not only in the “helmet wars” but in all things humans seem to disagree on on the internet.