Idaho Studded Tire Law
Run metal studs October 1 through April 30 (Idaho Code 49-948); off-season, May 1 to September 30, they draw a $67 equipment ticket. Idaho sets no GVW cap, so a loaded truck can legally run studs in season, but they must be the lightweight type the statute spells out, capped by stud weight (by size) and projecting no more than .06 inch. Studs are not chains and do not satisfy a posted chain-up order on Idaho's mountain routes.
Running studs in Idaho
Run metal studs October 1 through April 30 (Idaho Code 49-948); off-season, May 1 to September 30, they draw a $67 equipment ticket. Idaho sets no GVW cap, so a loaded truck can legally run studs in season, but they must be the lightweight type the statute spells out, capped by stud weight (by size) and projecting no more than .06 inch. Studs are not chains and do not satisfy a posted chain-up order on Idaho's mountain routes.
The window and winter-tire rules
- Season: October 1 to April 30 (Idaho Code 49-948). Metal studs are illegal on the road May 1 through September 30; retractable studs may be carried year-round (they may protrude beyond the wear bar only October 1 through April 30).
- No statewide M+S or 3PMSF winter-tire mandate. Idaho's chain-up order covers only Lookout Pass and Fourth of July Pass on I-90 and Lolo Pass on state highway 12, and it binds commercial vehicles over 26,000 lb (Idaho Code 49-948(5)). Studs are not chains and do not satisfy that order, so chain up when the sign is lit. The stud weight limits by size and the .06-inch projection limit in Idaho Code 49-948(4) bind tire retailers and installers. Truck weight cap: none, studs legal for trucks in season.
Idaho Studded Tire FAQ
Are studded tires legal in Idaho?
When can you use studded tires in Idaho?
What is the fine for illegal studded tires in Idaho?
Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://legislature.idaho.gov/statutesrules/idstat/title49/t49ch9/sect49-948/. See our Terms & Disclaimer.
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