The numbered state highway system covers approximately 3,135 miles of road in Colorado, subtracting the total miles of Interstate and US Highways from 9,100 miles of the state highway system.

The route markers used are separate from neighboring states rather than being consistent.

Most state highways are generally two lane roads with speed limits up to 65 miles per hour in rural areas but can drop as low as 30 miles per hour in served communities.

In urban areas, they can be six to eight lane expressways primarily in Denver and Colorado Springs.

State Highway 110 is the shortest route maintained by CDOT with a span of 0.186 miles (0.299 km).