Bicycle Highway-Access Laws in Montana
Last reviewed by BikeSize EditorialThis 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.
The rule
Bicycles are permitted on Interstate highways in Montana. Bicycles are permitted on Montana Interstate shoulders where no reasonable alternative route exists, under MDT bicycle policy. I-15, I-90, and I-94 are open to bicycles across most of their rural Montana mileage; specific tunnels, urban segments (Billings, Missoula, Bozeman), and bridges may be signed prohibited. Always check the on-ramp signage and the MDT Bicycle and Pedestrian Program map before entering.
What this means in practice
Interstate cycling is legal in Montana, but ride only where you have a wide, clean shoulder and exit at the first signed bicycle exit when conditions deteriorate.
Bigger roads, longer rides
Size a road bike for shoulders, group rides, and rural highways
Highway-access and group-riding rules favour riders who can hold a straight line at speed. Start with a frame that fits.
See the road sizing guide