Bicycle Safety

Bicycle helmets have been shown to reduce riders’ risk of traumatic brain injuries (TBI) by 88 percent, and laws requiring use have boosted the numbers of bikers wearing helmets. Head injuries account for about two-thirds of hospitalizations and about 75 percent of deaths in U.S. bicycle crashes. To further prevent some of these injuries, Seattle has created separate bike lanes and traffic lights on some roadways.

bicycle helmet

Start with the right size.

Every bike ride begins with putting on a helmet. But it’s equally important that you ensure a proper fit so your helmet can best protect you.

Size can vary between manufacturers. Follow the steps to fit a helmet properly. It may take time to ensure a proper helmet fit, but your life is worth it. It’s usually easier to look in the mirror or have someone else adjust the straps.

To find out the size of your head: Wrap a soft tape measure around your head, just above your eyebrows and ears. Make sure the tape measure stays level from front to back. (If you don’t have a soft tape measure, you can use a string and then measure it against a ruler.)

For the most comprehensive list of helmet sizes according to manufacturers, go the Bicycle Helmet Safety Institute (BHSI) website.


  • Coverage: A bike helmet should not sit too high or low on the rider’s head. To check, make sure the bottom of the pad inside the front of the helmet is one or two finger widths above the bike rider’s eyebrows. The back of the helmet should not touch the top of the bike rider’s neck.
  • Side straps: The side straps should make a “V” shape under, and slightly in front of the bike rider’s ears.
  • Chin straps: The chin strap should be centered under the bike rider’s chin and fit snugly so that no more than one or two fingers fit between the chin and the strap. Once the chin strap is fastened, the helmet should not move in any direction, back-to-front or side-to-side.

Make sure you can see your eyes, and that you can see straight-forward and side-to-side.

Replace any bike helmet that is damaged or has been involved in a crash

  • Look for a bike helmet with labels that:
    • Say U.S. Consumer Product Safety Commission (CPSC) certified. That label means that the helmet has been tested for safety and meets the federal safety standard.
    • Some bike helmets may also have a label stating that they are ASTM, Snell, or ANSI certified. These labels let you know that the helmet has also passed the safety tests of these organizations.
  • Find a bicycle route that is separated from traffic.
  • Use King County’s Regional Trails System (RTS) is one of the nation’s most extensive multi-use networks with more than 175 miles of trails for recreation and non-motorized mobility and commuting. Check out the map here.
  • Learn the rules of the road. Obey stop signs, traffic signals, speed limits on trails. Cycle in the same direction as other traffic unless the bike facility is marked otherwise. Ride predictably. Use hand-signals for your turns. When passing other riders or pedestrians, say “passing on your left,” then pass slowly.

Visit our Digital Resource Center to learn more about Bicycle Safety including Helmet Safety — plus, more injury and violence prevention topics year-round!

Sources: Centers for Disease Control, Washington State Department of Transportation, King County’s Regional Trails System (RTS), NHTSA and U.S. Consumer Product Safety Commission