Winter Travel Tips

Colorado Passenger Traction Law

The Passenger Vehicle Traction Law in effect on the I-70 mountain corridor from September to May. 

All motorists are required to have one of the following:
1.       4WD or AWD vehicle &  3/16” tread depth  
2.       Tires with a mud and snow designation (M+S icon) & 3/16” tread depth
3.       Winter tires (mountain-snowflake icon) & 3/16” tread depth
4.       Tires with an all-weather rating by the manufacturer & 3/16” tread depth
5.       Chains or an AutoSock

Adequate tires are critically important to navigating the I-70 mountain Corridor!  Check your tread with the simple quarter test: Insert a quarter into the tire tread upside down, with Washington's head going in first; if the top of George's head is covered by the tread, your tires are OK. (Do this test in multiple points around each tire.) If the top of his head is visible at any point, you need new tires.


The AutoSock is an easy-to-install traction device that meets the requirements of the Colorado Chain Law. Click here to find out where to find them!

Renting a Car?  

Ask the rental car company if their car’s tires meet the Colorado Traction Law.  Verify for yourself by performing the quarter test before you head up to the mountains.  If you get a ticket for a traction law violation, you are responsible for paying the fine, not the rental car company.

Consider leaving the driving to the experts!  All your options for getting to and around the mountains are at

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