Updated Transportation Impact Analysis Guidelines Available

The Knoxville-Knox County Planning Commission approved the update of the Transportation Impact Analysis (TIA) Guidelines (formerly known as the Traffic Access and Impact Study Guidelines and Procedures) at their regularly scheduled meeting on January 9, 2020.

In 1995, the Traffic Access and Impact Study Guidelines and Procedures were adopted within the Administrative Rules and Procedures of Knoxville-Knox County Planning. This was done so that staff, Planning Commissioners, and applicants would understand the potential impacts that a proposed development may cause to the existing transportation system along with any specific measures that may be needed to mitigate those impacts as part of the review process.

The updated guidelines, along with a pre-submittal form and review process diagram, are now available on our website

Notable updates to the guidelines

  1. Guidelines title has been changed from “Traffic Access and Impact Study Guidelines” to “Transportation Impact Analysis Guidelines”. Most references of “Traffic” have been changed to “Transportation” for a multimodal approach (including bicycle, pedestrian, and transit users instead of just motor vehicles) with the analysis more apparent, which is currently what our guidelines call for.
  2. Two types of transportation impact analysis have been identified depending upon the particular situation and conditions involved – a “Transportation Impact Letter” (TIL) and a “Transportation Impact Study” (TIS).
  3. The addition of the TIL adds flexibility to the guidelines by allowing a less detailed analysis, as opposed to a full Transportation Impact Study (TIS). There will not be a trip generation threshold for this type of analysis. 
    1. A TIL could be used in the following type of scenarios: Rural Retreat Use-on-Review proposals from a non-classified local roadway, an update to a previous TIL/TIS, change in land use from a previous development plan, minor additions to previous development plans, or in other situations requiring less analysis than a TIS.
  4. Requiring all development with direct access to a State Highway to consult with TDOT Region 1 Traffic Office to determine if TDOT regulations will apply.
  5. Addressing how to handle redevelopment and phased developments.
  6. The addition of a clause that allows the Executive Director of Knoxville-Knox County Planning to have the authority to require a Transportation Impact Analysis (TIA) if conditions are determined necessary to warrant it, regardless of the proposed development’s projected trip generation.
  7. Scope of studies broadened to allow discretion for review staff to require additional intersections to be studied if needed.
  8. Submitting a Pre-Submittal Transportation Analysis Determination form to Planning staff is strongly encouraged prior to submittal of a development application (a new form for applicants is attached to the end of Appendix B). This form is to determine whether a transportation analysis is required, the level of analysis, and which intersections will need to be studied. The TIA shall be submitted with an application for development, as currently required.
  9. A requirement for developments with vehicular trip generators of either a Level 2 or 3 is a Pre-Study Scoping meeting. A TIL or Level 1 TIS may require a pre-scoping meeting at the discretion of the review staff. This would ensure the applicant has a complete study with their application and has included the agreed upon study parameters and assumptions within their analysis. This would typically be completed after the Pre-Submittal Transportation Analysis Determination form and before the submittal of a transportation analysis with the application. A table that distinguishes the different analysis requirements has been created and attached to the back of Appendix B.
  10. Added the requirement of a comment response document, which is what we currently require. This allows for faster review of the corrections/revisions requested for an analysis.
  11. Providing further clarification on the following:
    1. Traffic count data (i.e. count to be no more than two years old and not during school closures)
      Summer traffic counts
      Trip Generation for Local Apartment and Shopping Center rates (which developments warrant those specific land use rates)
  12. Creation of a TIL/TIS guide and TIA review process diagram.