Traffic and Transportation

The Engineering Division works with the public at large, the development community, TDOT and the Federal Highway Administration, and our other City departments to increase safety, facilitate the movement of traffic through City streets, provide long-term planning and direction for the roadway network, and implement traffic improvement projects.

Traffic Impact Studies

Traffic Impact Studies (TIS) are required of certain developments that would produce a noticeable impact on the transportation systems of the City. The TIS helps the City determine traffic impacts and mitigation measures. If a development meets the following conditions, a TIS is required.

  1. Residential development with 75 or more dwelling units or non-residential development with 30,000 square feet of space or more.
  2. Mixed-use development that generates 75 peak hour vehicle trips or 750 daily vehicle trips.
  3. The project is located at or near an intersection that currently operates or is believed to operate at a Level of Service C or below.
  4. The project is located near a location identified by the City Engineer as a high crash/incident location or high concern location.
  5. A Traffic Impact Study is deemed necessary according to the City Engineer. The City Engineer has the final authority to require a Traffic Impact Study for any specific project.  

Examples of mitigation measures may include:

  • Safety improvements, such as signage or striping. 
  • Widening or resurfacing a roadway
  • Adding auxilliary turn lanes (left or right lanes)
  • Traffic signals or traffic signal equipment upgrades
  • Signal timing adjustments

Access Management

Access Management is the control of driveways and intersections to manage access to land development, while simultaneously preserving the flow of traffic on the surrounding road system in terms of safety, capacity, and speed. The Access Management Ordinance describes transportation design requirements that present a comprehensive approach to Access Management within the City of Columbia. 

Number of Accesses

The Access Management Ordinance restricts the number of accesses to City streets that are allowed by rights. Residential lots are permitted one access, while commercial and industrial uses over a certain size are permitted two. 

Driveway Spacing and Intersection Corner Clearance

Depending on the classification of roadways concerned (Arterial, Collector, or Local), driveways will require certain spacing offsets from one another and be a certain distance offset from intersections. This is to prevent conflicts with other turning movements, increase safety, and promote inter-connectivity.


Appeals to the standards and regulations of the Access Management Ordinance shall be heard in front of the Columbia Municipal Planning Commission (CMPC).