An overview of Idaho's bicycle laws, reviewed and cited to primary sources. Use the sections below to jump to a specific rule, or the Sources block at the end for the full citation list.
This guide is for general information only and is not legal advice. Laws change — verify current rules with your state DOT or a licensed attorney before relying on this for any legal matter. Read full disclaimer.
Helmet rules
Required under age
No statewide age requirement
Applies to passengers
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Standard
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Penalty
Idaho has no statewide bicycle-helmet law. Sun Valley and a handful of resort municipalities have considered local helmet ordinances for minors, but none are currently in force statewide.
Idaho Code § 49-722 lets bicyclists ride on sidewalks unless prohibited by local ordinance or official sign. A rider on a sidewalk has all the rights and duties of a pedestrian, must yield the right-of-way to pedestrians, and must give an audible signal before overtaking. Boise and Coeur d'Alene prohibit sidewalk cycling in their downtown business districts.
Idaho's DUI statute (Idaho Code § 18-8004) applies only to operators of a 'motor vehicle,' and § 49-114(11) defines motor vehicle to exclude bicycles. Cyclists impaired in public may still face reckless-driving or public-intoxication charges, but the DUI penalties — including a mandatory licence suspension — do not attach to bicycle operation.
White lamp on the front, visible from a distance of at least 500 feet.
Rear requirement
Rear reflector or light
Rear spec
Red reflector on the rear of a type approved by the Idaho Transportation Department, visible from a distance of 300 feet to the rear when directly in front of lawful upper-beam headlamps. A red rear lamp visible from 500 feet may be used in addition to the reflector.
ITD permits bicycle travel on the paved shoulders of rural Interstate segments in Idaho — including I-15, I-84, I-86, and I-90 — where no reasonable alternative exists. Urban Interstate segments through Boise and Coeur d'Alene are signed prohibited; long tunnels and certain bridges are individually posted.