Starting tomorrow, studded tires are allowed for passenger cars, and big trucks and other commercial vehicles must start carrying chains in preparation for wintry driving conditions, especially in the mountain passes.

The state Department of Transportation (DOT) today issued the following advisory:

“Washington law requires commercial vehicles and combinations of vehicles more than 10,000 pounds gross vehicle weight rating to carry sufficient tire chains between Nov. 1 and April 1. This includes some larger passenger trucks, SUVs, recreational vehicles and trucks hauling trailers. The State Patrol will have a special chain emphasis patrol in early November, to ensure commercial drivers have the proper number of chains required. State Patrol troopers will strictly enforce the Nov. 1 deadline. Failing to carry chains will cost $155. More information is available at www.wsp.wa.gov/traveler/docs/cvd/chainbw.pdf.

“DOT also reminds drivers that studded tires are only legal for use between Nov. 1 and April 1.”

In addition, the agency encouraged motorists “to visit their tire dealers for chains and find out about tires that provide traction and are legal for use year-round.”

DOT’s 24-hour reports on mountain pass conditions are online at www.wsdot.wa.gov/traffic/passes. Also online, at www.wsdot.wa.gov/winter, is information about winter travel, weather forecasts and how state crews clear roads.