1. Background
The purpose of the Transportation Impact Analysis (TIA) Guidelines is to assist applicants in preparing transportation studies for review by the City of Austin. These studies are required when a proposed development may impact multi-modal travel, including vehicle, pedestrian, bicycle, and transit systems. As new development occurs, it can alter existing travel patterns, and these changes must be evaluated to identify and address potential impacts.
A transportation study should:
-
Demonstrate understanding of existing and future transportation conditions around the site.
-
Assess the development’s impact on the transportation network.
-
Propose mitigation measures for any negative effects.
-
Show consistency with City-adopted plans such as the Austin Strategic Mobility Plan.
The study must:
-
Be signed by a licensed professional engineer with relevant transportation engineering experience.
-
Include a general project description (location, land uses, buildout year, etc.) and trip generation estimates for daily and AM/PM peak hours.
-
Provide intersection capacity analysis and a multi-modal assessment.
-
Recommend mitigation improvements for all travel modes (vehicular, pedestrian, bicycle, and transit), with associated cost estimates and conceptual plans.
-
Remain valid for up to five years from the date of City or Commission approval.
2. Authority and Determination
Under Chapter 25, Article 3, Section 25-6 of the City of Austin’s Land Development Code (LDC), transportation studies may be required for zoning or site plan applications based on trip generation and project type. The following studies may be required:
-
Transportation Demand Management (TDM) Plan: Required for developments generating 2,000+ unadjusted daily trips. May also be required at zoning under certain conditions.
-
Transportation Assessment (TA): Required for developments generating 2,000–4,999 unadjusted daily trips. At the discretion of the Lead Development Review Engineer, a Zoning Transportation Analysis (ZTA) may be substituted for zoning applications.
-
Full TIA: Required for developments generating 5,000+ unadjusted daily trips. A ZTA may be substituted for zoning applications at the discretion of the TDS Lead Engineer.
-
Neighborhood Traffic Analysis (NTA): Required for projects accessing residential streets that generate 300+ net new daily vehicle trips, or for public primary/secondary educational facilities. (See LDC §25-6-114 for details.)
-
Zoning Transportation Analysis (ZTA): Required for zoning applications generating 2,000+ unadjusted daily trips when neither a TA nor Full TIA is required.
TIA Determination Process:
Applicants must submit a TIA Determination Worksheet to the Transportation Development Services (TDS) Division before beginning a transportation study. The worksheet must include:
-
Project location and description
-
Applicant and application details
-
Existing and proposed land uses and intensities
-
Trip generation data
-
Proposed site access
-
Site development phases
TDS will review the worksheet, complete the trip generation calculations, and determine which type of transportation study (if any) is required based on LDC thresholds.
Note:
-
Appeals regarding TIA determinations must be submitted to TDS.
-
The latest Institute of Transportation Engineers (ITE) Trip Generation Manual must be used.
-
Trip reductions for internal capture, pass-by, or TDM are not allowed in the initial determination.
-
Reductions based on existing land uses may be considered with occupancy documentation.
Alternative trip generation data sources (e.g., NCHRP Report 684) may only be used if the ITE manual lacks relevant data.
Even if a formal transportation study is not required, mitigation measures may still be necessary in accordance with LDC Section 25-6-101
Our Services are available throughout City of Austin with Zipcodes78654, 76574, 78641, 78669, 78653 78612, 78610,78617.