CDOT Speed Management Program

CDOT Speed Management Process

The CDOT process for setting speeds is based on the Speed Zone section of the Manual on Traffic Control Devices (MUTCD) 11th Edition, published in January 2004. CDOT uses the recommended six primary factors in establishing speed zones including Roadway Environment, Roadway Characteristics, Geographic Context, Reported Crash Experience, Speed Distribution of Free Flow Vehicles, and Past Speed Studies.

The CDOT Speed Management Process has six steps:

  1. Submit a Speed Study Request:  A Region Traffic team submits a Speed Study Request that may require Local Agency coordination.  This provides context to the request and also informs CDOT of the current roadway conditions.
  2. Evaluation:  The Field Regulatory Operations team performs an engineering evaluation that collects safety and crash experience data, geometric and operations characteristics, and past speed studies.
  3. Planning of the Study:  The Field Regulatory Operations team performs a pre-field work process that determines the best approach to data collection, regulatory signage field observations, and driving the curves. 
  4. Data Collection and Analysis:  The Field Regulatory Operations team performs an engineering analysis to consolidate and analyze all the data to determine an appropriate speed limit, weighing all gathered information. CDOT uses a custom Expert Speed Setting tool as a starting point and then factors in the contextual and field data to finalize a speed limit recommendation.
  5. Region Review:  The regions review the speed limit recommendation before speed limit setting recommendations are implemented.

Colorado Open Records Act (CORA) requests for the Colorado Department of Transportation (CDOT) must be submitted through the CDOT CORA office. Please see the CDOT CORA website for more information and instructions:

School Studies

Studies to establish School Zones are CDOT's highest priority due to the school year and workload schedules. The Field Regulatory Operations team performs school studies for schools adjacent to state highways to determine if school zones and/or school signage are warranted. Schools and local government agencies can request School Studies through the local CDOT Region Traffic Engineer.  Schools and/or School districts are encouraged to have all School Zone Requests to CDOT no later than the first week of April in a given school year.


Speed Studies

The Field Regulatory Operations team performs speed studies on state highways to determine proper speed limits. Speed Studies are usually conducted after a highway has been reconstructed or if a new development is having an impact on the highway. A speed study can be localized to small sections of state highways or for longer sections of a highway. Local government agencies can request Speed Studies through the local CDOT Region Traffic Engineer. Concerned citizens may request a speed study by working with local agencies.


No Passing Zone Studies

The Field Regulatory Operations team performs No Passing Zone Studies to determine the length of no-passing zones on all two and three-lane state highways. The criteria are based on vehicle performance during the passing maneuver, the premise that sight distance should be provided at the critical position when the passing and passed vehicle are abreast, and the evaluation of traffic control devices in providing the required visual information at this critical position. Minimum passing sight distance is defined as the sight distance necessary at the critical position to permit a passing driver to perceive an opposing vehicle at a distance sufficient to allow safe completion of the passing maneuver. Safety critical passing zone studies are initiated by the Region Traffic Office and conducted by the Field Regulatory Operations team.