American Association of State Highway & Transportation Officials
Colorado Department of Transportation (CDOT)
Federal Highway Administration (FHWA)
Institute of Transportation Engineers
Traffic Calming: State of the Practice
Manual includes history, terms, real life studies, impacts and more.
Manual on Uniform Traffic Control Devices
USGS Water Resources of Colorado
Includes online current and historical water information, including real-time surface water conditions, ground water, water-quality.