The City of Thornton maintains 132 traffic signals and is adding approximately three per year. Traffic signals are installed only after meeting warrants established in the Manual of Uniform Traffic Control Devices published by the Federal Highway Administration.

The traffic signals on Colorado Boulevard, Washington Street, 120^th Avenue, 136^th Avenue, Thornton Parkway, 88^th Avenue, 84^th Avenue, and Holly Street South of 120^th Avenue are on coordinated traffic signal systems. The traffic signals along 104^th Avenue are also coordinated, but maintained from I-25 to Irma Drive by the City of Northglenn.

To request a warrant study for a new traffic signal or to report operational issues at an existing traffic signal, please call the Traffic Engineering Division at 720-977-6500 or send an email to Infrastructure.