Utah's Class I and Class II Traction Segments, Explained
Date Published
Utah's traction rule is built around designated stretches of highway rather than the state as a whole, and the designation carries the substance.
Two classes
Under Utah Admin. Code R920-6, a Class I Traction Segment is a defined part of a highway where UDOT, the Utah Highway Patrol or a designated local law enforcement agency may require vehicles over 12,000 GVW to provide traction devices.
A Class II Traction Segment is a defined part of a highway where the same authorities may require traction devices or four-wheel drive for all vehicles. The rule adds that a Class II segment may also be operated as a Class I when conditions warrant, so the same stretch of road can bind differently on different days.
When it binds
The designation alone does not require anything. Under R920-6-4, the requirement takes effect when road surface conditions warrant, as determined by UDOT, UHP or a designated local law enforcement agency. UDOT issues a Traffic Engineering Order establishing each segment and its class, maintains and publishes the list on its website, and communicates changes to its region offices, UHP, county offices and local law enforcement.
What traction device equipped means
R920-6-3 defines the term more broadly than chains. Traction devices are devices that improve traction of tires on icy or snowy road by placing high friction objects between the tires and the road, and the rule gives tire chains, sand distribution devices and tire studs as examples.
A vehicle is traction device equipped when it carries traction devices on all drive tires, with one exception: in the case of dual tires, devices are required on at least one of the two tires in the dual mounting.
There is a lighter-vehicle alternative. A vehicle under 12,000 GVW with Three Peak Mountain Snowflake snow tires on all wheels counts as traction device equipped.
Why the class matters to a heavy vehicle
For a commercial driver the practical difference is the threshold. On a Class I segment the requirement reaches vehicles over 12,000 GVW and leaves passenger traffic alone. On a Class II segment it reaches everyone. Knowing which class a canyon is running tells you whether the queue ahead is being filtered on equipment or simply held.
A sourcing note
The text above was read from the Cornell Legal Information Institute mirror of the Utah Administrative Code, because the state rules site now serves only a redirect to a client-rendered application. It should be re-checked against the official Utah Administrative Code before being relied on for a compliance decision.