Northwest NEWS

November 19, 2001


New traction advisory notices for mountain pass highways

Beginning this year, motorists will notice new advisories on all mountain pass reports posted on highway signs, the WSDOT Web page (, the 1-800-695-ROAD telephone number and Highway Advisory Radio (530 AM and 1610 AM). The new advisories will help motorists understand the legal requirements and clarify restrictions for truck drivers.
   Heavy trucks and four-wheel drive vehicles, due to their higher center of gravity, are required to carry chains between Nov. 1 and April 1 when traveling through the following areas: Columbia Gorge, Satus Pass, White Pass, Chinook Pass, Snoqualmie Pass, Blewett Pass, Stevens Pass, North Cascades Highway.
   The Washington State Patrol can require chains to be installed when conditions warrant on other highways. Two-wheel drive passenger vehicles, unlike heavy trucks and four-wheel drive vehicles, are not legally required to carry chains in these locations. However, drivers must put on chains when required, so WSDOT recommends all drivers carry chains.
   New Advisories
   Traction Advisory: Oversize Vehicles Prohibited While oversized vehicles (over-height, over-weight and over-width) are not allowed, there are no restrictions for passenger vehicles.
   Vehicles over 10,000 lbs. GVW - Chains Required/Passenger vehicles, all season tires required: Passenger vehicles must have "all season" tires with at least 1/8 of an inch of tread depth and are marked "mud and snow," "M&S" or "M/S" on the sidewalls. Approximately 98 percent of all tires in use meet these requirements.
   All Vehicles - Chains Required, Except All-Wheel Drive: Self-explanatory, but the Washington State Patrol can require vehicles with all-wheel drive to put on chains if the trooper at the scene feels that conditions require them. All-wheel drive passenger vehicles are legally required to carry one pair of chains.