Colorado's mandatory chain law expanded, includes I-70 mountain corridor, highways west of I-25

Colorado's mandatory chain law has been expanded this year with the new rules going into effect back in September before it started snowing. The Colorado State Patrol and Colorado Department of Transportation explained the new commercial motor vehicle chain law requirements on Tuesday. 

The law expands the geographical areas where commercial motor vehicles are required to carry chains from September 1 to May 31. It includes I-70 from Dotsero to Morrison and most state and federal highways west of I-25. 

The law also restricts commercial motor vehicles from operating in the left lanes in certain portions of the I-70 mountain corridor where curves or steep grades exist. 

According to CSP and CDOT, Colorado has struggled with extended closures to the I-70 mountain corridor during extreme weather events and winter driving conditions. I-70 is the only east-west interstate in the state. 

To reduce traffic disruptions and road closures, state lawmakers expanded existing chain laws to make commerce safer, particularly on steep inclines, preventing potential crashes and minimizing the risks of getting stuck.