Mid-season check-in: Winter weather-related crashes and closures down on I-70 as updated Traction Law takes effect in Colorado

News Release

February 13, 2020 - Statewide Traffic Safety - CDOT offers tips for travelers ahead of busy Presidents Day holiday weekend

To download CDOT’s Winter Wise safety education materials, visit: https://www.dropbox.com/sh/ofvgro4q8mkpd0p/AAA593obdeQ-7pDRndQohD0la?dl=1

STATEWIDE  The I-70 mountain corridor is one of Colorado’s most highly-traveled roadways, and traffic increases during busy times like the upcoming Presidents Day weekend. The corridor is also frequently subject to dangerous winter weather driving conditions. So far this winter, data shows crashes, spinouts and closure times have decreased compared to last year.

Between October and December 2019, preliminary data shows 124 crashes were reported on the I-70 mountain corridor, resulting in more than 114 hours of partial and full-lane closure time. That number is down 21 percent from more than 144 hours of closure time during the same period in 2018. Additionally, 54 non-crash emergency responses (mechanical issues, fires, spin-outs/slide-offs) were reported, causing more than 28 hours of closure time. This closure time is also down from 2018, decreasing by 35 percent from the nearly 43 hours of closure time during the same period last year.

“It’s a good time to check in on safety efforts so far this winter season and share safety reminders as we head into the busy Presidents Day holiday weekend,” said Andrew Hogle, CDOT Public Information Officer. “While it’s difficult to compare safety data to past year’s statistics because there are factors at play like varying snowfall amounts and driving conditions, it’s encouraging to see that crashes and delay times have decreased so far this year. Coloradans and tourists are trending in the right direction by driving more safely and following the Traction Law. There’s still plenty of winter weather ahead though — so we urge all Colorado motorists to continue to adhere to the Traction Law and follow safe winter driving practices.”

Last year, updates to the Traction Law went into effect, requiring that all motorists have either an all-wheel or four-wheel drive vehicle, mud/snow tires (M+S icon), winter tires (mountain-snowflake icon), or tires with an all-weather rating. The law also increased the minimum tread depth for tires on all vehicles — including those with four-wheel drive and all-wheel drive — to three-sixteenths of an inch. In addition, from Sept. 1 to May 31, all vehicles traveling on I-70 between Morrison and Dotsero must follow the Traction Law or carry chains or an AutoSock®. If the weather worsens, CDOT will activate the Chain Law, requiring all vehicles to have chains or an AutoSock®. For more Traction Law and Chain Law information and downloadable materials, visit codot.gov/travel/winter-driving/tractionlaw.

“The Traction Law and safety closures are an important piece of how CDOT keeps travelers safe,” said Hogle. “While some may feel it’s an inconvenience, these measures are put in place to protect everyone on the road.”

CDOT implemented highway safety closures 114 times on I-70 between October and December 2019 and deployed 252 courtesy patrols. A safety closure is a precaution taken during inclement weather to reduce the probability of traffic incidents, increased congestion or other safety-related factors. During a safety closure, traffic may be stopped on the interstate, turned around or directed to an exit. Safety closures help decrease delay times, and, above all, keep people safe. To view and download CDOT’s safety closure informational video, visit bit.ly/CDOTSafetyClosureVideo.

In addition to updating Colorado’s Traction Law, last year, Gov. Polis signed a bill that increased penalties for motorists who pass a group of snowplows operating in tandem formation (arranged diagonally) — making it a Class A traffic offense.

Looking ahead to Presidents Day weekend — one of the busiest weekends of the year along the I-70 mountain corridor — CDOT is offering motorists the following tips and reminders:

  • Make sure your vehicle is Traction Law compliant. If you plan to drive on I-70 any time through May 31, you must have EITHER:
    • 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 AutoSock®      
  • Obey the Tandem Snowplow Law. Never pass a snowplow on the right, and never attempt to pass a group of snowplows operating in tandem formation. This is now a Class A traffic offense.
  • Avoid traveling during peak times. Goi70.com offers weekend travel forecasts that are updated every Thursday afternoon to help you plan.
  • Consider carpooling or using mountain transit to cut down on congestion. Bustang and Snowstang both offer service to and from the mountains and Bustang Outrider offers service in rural regions.
  • If you are stopped on I-70 near the Eisenhower Tunnel, it may be due to safety metering. Safety metering helps control the flow of traffic, reduce accidents and keeps the tunnel clear for emergency vehicles to get through. Please be patient.
  • An Express Lane is available on eastbound I-70 between Empire and Idaho Springs for a toll.


CDOT’s Winter Wise campaign focuses on education, tools and resources to help keep drivers safe on Colorado’s winter roads. To learn more and view helpful tips for winter driving, visit winter.codot.gov. For specific information about I-70 and other highway travel conditions, motorists can call 511 or check COtrip.org. Additionally, drivers can check Twitter for up-to-date travel information via @ColoradoDOT. For more detailed information about the Traction and Passenger Vehicle Safety Laws, snowplow laws, safety stats and frequently asked questions, visit winter.codot.gov.  


In early 2019, CDOT announced its Whole System — Whole Safety initiative to heighten safety awareness. This initiative takes a systematic, statewide approach to safety combining the benefits of CDOT’s programs that address driving behaviors, our built environment and the organization's operations. The goal is to improve the safety of Colorado’s transportation network by reducing the rate and severity of crashes and improving the safety of all transportation modes. The program has one simple mission—to get everyone home safely.