State has a Far Right as Practicable Requirement

Montana requires a slower bicyclist to ride in the right-hand lane or a paved shoulder, but how far right is judged by the bicyclist's own safety assessment, and riders are not required to ride through hazards or without a reasonable margin of safety.

Allows Two Abreast Riding

Montana allows riding two abreast on a paved shoulder or in a parking lane without condition, and on a multi-lane roadway only if it does not impede traffic more than single-file riding would; on an ordinary two-lane roadway, single file is the default.

Single File is Required

Montana's default rule for roadway riding is single file; riders may go two abreast only on an exclusive bicycle path, while overtaking, in a parking lane, or on a multi-lane roadway when it does not impede traffic more than single file would.

Has a Safe Passing Law

Montana requires a motorist to pass a bicyclist only when it can be done safely, but state law sets no specific minimum passing distance (e.g., three feet).

Helmets are required on the road

No statewide bicycle helmet requirement appears in Title 61, chapter 8, part 6; some cities (e.g., Bozeman, Billings) require helmets for minors by local ordinance.

If Bike Lanes are present, they are required ( except when unsafe )

Montana's bicycle-operation statute permits but does not require riding on a paved shoulder or bike lane when one is available.

Riders may use the sidewalks

Montana allows sidewalk riding statewide, subject to yielding to pedestrians, giving an audible signal before passing, and following the same rules as a pedestrian; riding is barred only where a specific traffic-control device prohibits it.

Does the Impeding Statute Apply to Bikes

Montana's core impeding-traffic rule (§ 61-8-311(1)) is limited to motor vehicles and does not reach bicycles. However, § 61-8-311(2)'s pull-over duty for a "slow-moving vehicle" trailed by four or more vehicles is not limited to motor vehicles by its text, and could apply to a bicyclist in that specific circumstance; separately, riding two abreast is conditioned on not impeding traffic more than single file would.

Whether cyclists may treat stop signs as yield signs (the "Idaho stop").

Montana has no law letting bicyclists treat stop signs or red lights as yields; bicyclists are subject to the same stopping duties as any other vehicle driver.

Restrictions exist on e-bikes and usage

Montana defines an electrically assisted bicycle by a power/speed cap — its motor may not propel a 170-pound rider faster than 20 mph on a paved, level surface — rather than the three-class system some states use, and treats it as a bicycle for all other purposes.

Allows the concept of Contributory Negligence that allows any contributory fault resuls in 'no fault'

Montana uses modified comparative negligence: a claimant recovers, with damages reduced by their share of fault, only if their fault does not exceed the combined fault of the parties they are suing; a claimant more than 50% at fault recovers nothing.