The Colorado State Patrol (CSP) and the Colorado Department of Transportation (CDOT) are the only two entities that can close interstate, federal or state highways in Colorado. They have different criteria for using their closure authority.

     The CSP closes highways because of accidents. The CSP can keep a highway closed because of hazardous materials situations and because the highway is blocked by wreckage, debris or in some cases evidence that still needs processing. The CSP can not close highways because of road and weather conditions although troopers do report to CDOT on highway conditions statewide and do recommend closures and at times chain restrictions.

     CDOT closes highways because of road and weather conditions including blizzards, slides and sometimes because of the potential for slides (snow, mud, or even rockslides). Overnight closures are rare but not unknown. Major blizzards have closed some highways for days. Massive snowslides, mudslides and even rockslides have kept buried or damaged highways closed overnight and even in some cases for several days.

     Both the CSP and CDOT are dedicated to keeping highways open and to reopening closed routes as quickly as possible while still adhering to the highest safety standards at all times.