Winter Driving

CDOT image hi res


A chain law restriction for vehicles weighing less than 26,001 lbs. including passenger vehicles, crossovers, SUVs, and small trucks can be put into effect in Colorado at any time when weather conditions are severe, primarily on roadways with significant ascending and descending grades.  This restriction is Code 15. 

When Code 15 of the chain law is in effect, all vehicles must have one of the following in order to proceed:

  • Snow tires with a minimum of 1/8” of tread; or
  • All weather tires with mud and snow (M/S) mark with 1/8” of tread; or
  • Four-wheel drive with 1/8” of tread; or
  • Traction devices (chains, auto-sock, etc.) for two drive tires.
NOTIFICATION: When the chain law is in effect, drivers will be notified by electronic message signs; 511 traveler information;; and media.

WHEN IS YOUR TREAD SUFFICIENT? It’s quick and easy to test. Insert a quarter upside down into your tire tread (with George Washington’s head first). If the top of the head is covered by tread, you’re good to go. If the top of his head is visible at any point around the tire (test multiple points), you can’t drive when Code 15 of the chain law is in effect. You also likely need new tires.

SAFE DRIVING AROUND SNOWPLOWS: During spring, winter, and fall you will often see CDOT’s large orange snowplow trucks clearing roadways to help make your drive much safer. In return, you can help them in the following ways.

  • Don’t crowd the plow. Give them space to work.
  • Don’t tailgate.
  • Avoid driving alongside the plow. Because of the height and length of the
  • vehicle, a plow driver’s field of vision is limited. You may not be in the
  • plow driver’s field of vision and the driver may not know you are there.
  • Never pass a snowplow on the right. You will be caught in hard snow,
  • ice, and rock thrown up by the plow blade.
  • If you must pass a snowplow, do so on the left. Allow plenty of distance.
MOVE IT TO THE SHOULDER AFTER MINOR ACCIDENTS: Colorado’s “Move It” law requires motorists involved in minor accidents to move your vehicle immediately out of traffic to a safe location:

  • When the vehicle is driveable;
  • When no drugs or alcohol are involved; and
  • When there are no injuries.
DID YOU KNOW? Traffic accidents, rather than volume, account for up to 60% of all traffic delays. A minor accident that takes just 10 minutes to clear can delay traffic by up to one hour. A one-lane blockage on a three-lane freeway reduces the highway’s capacity by more than 50%.