Utah Studded Tire Law

Running studs in Utah

The calendar says October 15 to March 31 (Utah Code 41-6a-1636), but for a rig the weight cap decides it. Tungsten carbide studs are illegal on any vehicle with a GVWR over 9,000 lb unless it's an emergency vehicle or school bus. So a loaded truck cannot run studs in Utah at all. Studs cap at .050-inch projection. When UDOT puts the Traction Law in effect, a truck at 12,000 lb GVWR or more on a Class 1 segment needs chains, cable chains, or snow socks on all rear drive tires, unless it is AWD or 4WD on M+S or 3PMSF tires (R920-6-3).

The window and winter-tire rules

• Season: October 15 to March 31 (Utah Code 41-6a-1636), written as October 15 through December 31 and January 1 through March 31, and only on vehicles with a GVWR of 9,000 lb or less (emergency vehicles and school buses excepted), so not on a loaded truck.
• Truck weight cap: tungsten carbide studs are barred on any vehicle with a GVWR over 9,000 lb (except emergency vehicles and school buses), so a loaded truck can't run studs here in any month. Studs limited to .050-inch projection. UDOT's Traction Law counts tire chains, tire studs, and snow socks as traction devices (R920-6-2). On a Class 1 segment a vehicle at 12,000 lb GVWR or more needs traction devices on all rear drive tires, one per dual pair, unless it is AWD or 4WD on M+S or 3PMSF tires (R920-6-3). The stud option is closed to a heavy truck, so it runs chains, cable chains, or snow socks. See the Utah chain-law page.

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