Winter Driving Information from CDOT

Whether you’re a native, a new resident or a tourist, driving in Colorado winter weather can be dangerous if you’re not prepared. As we enter the winter months, CDOT wants to remind all Colorado roadway users of the following tips to stay safe.


  • Have a plan. Prepare a winterized emergency vehicle kit. Always plan your route in advance and be sure to let someone know your route and ETA. Check road conditions at
  • Check your tires. It’s tire buying season! Make sure to check the air pressure in all tires, including your spare, and that your tires have good tread — at least 3/16”.
  • Perform a safety check. Give your vehicle a tune-up before long trips. This includes getting an oil change if necessary, inspecting the battery, brakes and pads and wiper blades. Ensure you have a full tank of gas, and lastly, check your headlights, brake lights, turn signals, emergency flashers and interior lights.
  • Know the laws. When weather conditions warrant, CDOT implements Passenger Vehicle Traction and Chain Laws. Head over to CDOT’s Traction & Chain Laws page for the most up-to-date laws.


Having adequate tires with proper tread depth is the first step motorists should take before choosing to drive on winter roads. Between October 2020 and April 2021, 262 passenger vehicle crashes were reported on the I-70 mountain corridor in addition to 91 non-crash emergency responses (mechanical issues, fires, spinouts/slideoffs). Many of these crashes, spinouts and slideoffs were due to poor quality tires.

Having adequate tires is not only safe; it’s also the law. Last winter, CDOT activated the Passenger Vehicle Traction Law 166 times on the I-70 mountain corridor alone. CDOT can implement the Passenger Vehicle Traction and Chain Laws on any state highway.

During a Passenger Vehicle Traction Law, all motorists are required to have one of the following:

  • A 4WD or AWD vehicle and 3/16” tread depth
  • Tires with a mud and snow designation (M+S icon) and 3/16” tread depth
  • Winter tires (mountain-snowflake icon) and 3/16” tread depth
  • Tires with an all-weather rating by the manufacturer and 3/16” tread depth
  • Chains or an approved alternative traction device


  • Drive for the conditions. Don’t drive faster than you can see ahead and don’t forget to turn on your headlights! If you’re stuck in a serious storm, do not leave your vehicle. Run the engine periodically and wait for help.
  • Bow to the plow. It is illegal to pass a snowplow when it is operating its lights and operating in a tandem formation with one or more snowplows. Don’t crowd the plow, be sure to remain three to four car lengths behind snowplows.

Travelers are urged to “know before you go.” Gather information about weather forecasts and anticipated travel impacts and current road conditions prior to hitting the road. CDOT resources include: