This amendment changes the definition from Commercial/Bus/Recreational vehicle to vehicles over 12,000 GVW. This definition matches left lane restrictions for heavy vehicles and is more descriptive. This change is likely to have little net effect since the visual cues used by law enforcement to identify these vehicles will not change. Changes to allowed traction devices as follows: All Vehicles - the rule expands traction options, allowing drivers to pick the one that meets the owners needs. Since chains are relatively inexpensive, this will not likely change out-of-pocket costs significantly, but some drivers will be able to substitute traction devices. Removes the M/S designation from being acceptable for two-wheel drive vehicles. 3PMSF tires still allowed. This amendment will require two-wheel-drive vehicles that in the past had M/S tires to either buy chains or 3PMSF tires. This is the biggest increase in cost. Changes affecting AWD/4WD: clarifies requirements - no significant change from prior rule. Changes when chains are required - existing rule requires chains in the vehicle between October 1 and April 30. This amendment requires operators to have traction devises in the vehicle when UDOT or the Utah Highway Patrol (UHP) has determined that conditions warrant them, and the traction devices must be mounted, not just in the vehicle. This means that travelers who choose to avoid inclement weather are not required to buy traction devices. This should be a minor reduction in statewide costs. This change accommodates chain restrictions for heavy vehicles only. Certain segments of road that previously required chains will not require traction devices on all passenger cars/light trucks. This amendment makes several changes with minor effects - mostly to reduce cost, and one significant cost increase, which is for non-AWD/4WD vehicles traveling during storms. This amendment requires these vehicles to have traction devices installed or proper snow tires.