Mileposts (or mile markers) along highways and their locations collection during GPS mapping efforts in the early 2000s from the Colorado Department of Transportation (CDOT).

CDOT gives a letter grade to overall roadway condition. It is a combination of the percent of highway pavement determined to have high or moderate Drivability Life and the level of service (LOS) delivered by CDOT’s maintenance program. The Department in 2013 changed its way of evaluating pavement condition. Grades for previous years are not directly comparable.

Colorado Department of Transportation five year IT roadmap.

County boundaries and area, from the Colorado Department of Transportation (CDOT) for 64 counties in the state of Colorado.

Number of traffic fatalities each year on Colorado roads

Number of people involved in traffic incidents on Colorado roads that resulted in evident injuries, whether incapacitating or not.

The tunnel maintenance program tracks CDOT progress in maintaining tunnels on the State Highway System. A letter grade is given every year on maintenance activities at the Eisenhower-Johnson and Hanging Lake tunnels on I-70. Maintenance on these aging tunnels includes tunnel washing and sweeping, ventilation maintenance, snow removal, emergency response and round-the-clock television surveillance.

County boundaries and area, from the Colorado Department of Transportation (CDOT) for 64 counties in the state of Colorado.

CDOT’s maintenance program establishes a target letter grade it expects to achieve for snow and ice control each year. During the winter, CDOT maintenance workers complete surveys to grade their performance using established criteria based on the year’s budget. Higher grades are typically achieved during lower-cost, milder winters.

Airport locations, nearby city, recreation in the area, and more with associated data (hours, annual number of passengers, etc) from the Colorado Department of Transportation (CDOT).