Oregon Department of Transportation reports heavy and continuous snow on Interstate 5's Siskiyou Summit, and chains are required on all vehicles except those with 4-wheel drive,

Traction tires alone are not enough, according to ODOT's Trip Check website, which reported an accumulation of seven inches of new snow on the roadway this morning and 15 inches on the roadside.

Even 4-wheel drive vehicles must have chains if they are towing.

For updated road conditions go to www.tripcheck.com.