San Antonio Region Traffic Impact Study and Analysis Requirements
What Is a Traffic Impact Study and Why Is It Important?
A Traffic Impact Study (TIS), also commonly referred to as a Traffic Impact Analysis (TIA), is a technical evaluation of how a proposed development will affect the surrounding roadway network. The study estimates the number of trips generated by a project, identifies how those trips distribute across nearby streets and intersections, and assesses whether existing or planned transportation infrastructure can safely and efficiently accommodate the additional traffic.
In the San Antonio metropolitan area, Traffic Impact Studies are commonly required by reviewing agencies such as the City of San Antonio, Bexar County, the Alamo Area Metropolitan Planning Organization (AAMPO), and the Texas Department of Transportation (TxDOT) when a development exceeds certain trip generation levels, affects roadway access, or meets specific size or land-use criteria. Surrounding municipalities within the region may also impose their own traffic study requirements based on local development regulations.
The purpose of a Traffic Impact Study is not only to quantify traffic impacts, but also to identify appropriate mitigation measures—such as roadway or intersection improvements, signal timing adjustments, access management modifications, or turn lane additions—to maintain acceptable traffic operations and safety. A well-prepared Traffic Impact Study helps ensure that development projects move forward without creating congestion, safety concerns, or operational deficiencies, while providing agencies with the technical documentation needed to support informed permitting and access decisions. For developers, completing a Traffic Impact Study early in the project lifecycle reduces the risk of review delays, design changes, or unforeseen infrastructure costs during agency coordination.
Which Agency Reviews Your Development in San Antonio?
The agency responsible for reviewing a Traffic Impact Study (TIS) in San Antonio depends on the project location, roadway ownership, and site access conditions. In the San Antonio metropolitan area, this determination is typically made by confirming municipal boundaries, Bexar County jurisdiction, and whether the proposed development connects to a TxDOT-maintained roadway. Identifying the correct reviewing agency early is a critical step in the San Antonio Traffic Impact Analysis (TIA) process and can significantly reduce permitting delays.
The appropriate reviewing agency for a Traffic Impact Analysis in San Antonio can usually be identified using the following steps:
- Confirm whether the site is within an incorporated city in the San Antonio region: If the project is located within the corporate limits of the City of San Antonio or nearby municipalities such as Schertz, Converse, Live Oak, or other surrounding cities, that city is typically the primary reviewing authority for the Traffic Impact Analysis.
- Check if the site is outside city limits but within Bexar County: Developments located outside incorporated city boundaries within the San Antonio area are generally reviewed by Bexar County or the applicable adjacent county, depending on roadway ownership and project location.
- Determine whether the development impacts a TxDOT roadway: If site access is provided from a state highway, frontage road, interchange ramp, or any facility maintained by the Texas Department of Transportation (TxDOT San Antonio District), TxDOT review is typically required, either as the primary reviewing agency or in coordination with the City of San Antonio or Bexar County.
- Identify overlapping or joint jurisdiction cases in San Antonio: Some developments in the San Antonio region require coordination between multiple agencies—such as a city and TxDOT or Bexar County and TxDOT—depending on roadway jurisdiction, access location, and the magnitude of projected traffic impacts.
- Confirm Traffic Impact Analysis requirements through agency coordination when needed: For projects near municipal boundaries, within extraterritorial jurisdictions (ETJs), or involving complex access or roadway conditions in San Antonio, direct coordination with the reviewing agency is commonly used to confirm TIA requirements, study scope, and documentation expectations.
Traffic Impact Analysis Requirement per Agency
| Agency or Jurisdiction | TIA Threshold | Notes |
|---|---|---|
| City of San Antonio | ≥76 peak-hour trips | TIA required at 76 or more peak-hour trips; smaller projects submit a trip-generation worksheet. Additional triggers apply for major modifications, old TIAs, or access changes. |
| TxDOT San Antonio District | Case-specific | No fixed threshold; TIA or engineering study required based on access, safety, and roadway classification. Auxiliary lane warrants commonly begin at 50 peak-hour vehicles on high-speed roadways. |
| Bexar County (Unincorporated) | ≥76 peak-hour trips | County adopts City of San Antonio UDC thresholds. Mitigation and review mirror San Antonio requirements. |
| Alamo Area MPO (AAMPO) | Not applicable | Regional planning agency only; does not review site-specific TIAs. Provides travel demand modeling for long-range planning. |
| City of Leon Valley | ≥100 peak-hour trips | Developments below 100 peak-hour trips are exempt. TIA required when the threshold is met or exceeded. |
| City of Balcones Heights | Case-specific | No published numeric threshold. Traffic studies determined through engineering review and TxDOT coordination. |
| City of Live Oak | >100 peak-hour trip increase | New TIA required when a project adds more than 100 peak-hour trips. Projects below the threshold are exempt. |
| City of Universal City | ≥100 peak-hour trips | TIA required at 100 or more peak-hour trips. Projects below the threshold do not require a study. |
| City of Schertz | Case-specific | No numeric threshold published. Requirement determined by city engineer during development review. |
| City of Converse | Case-specific | No published threshold; TIA needs determined during engineering review. Coordination with county or nearby jurisdictions may apply. |
| City of Selma | Case-specific | No numeric TIA trigger in code. Traffic studies reviewed individually, often with TxDOT coordination. |
TIA San Antonio Frequently Asked Questions
There is no technical difference. The terms Traffic Impact Study (TIS) and Traffic Impact Analysis (TIA) are used interchangeably by reviewing agencies to describe the same traffic evaluation process.
TIA requirements depend on project location, estimated trip generation, and roadway jurisdiction. An initial screening or technical memorandum is often used to confirm whether a full Traffic Impact Analysis is required by the reviewing agency. Civotec routinely performs these applicability reviews. For screening or technical memorandum preparation, contact info@civotec.com
Reviewing agencies commonly include the City of San Antonio, surrounding municipalities, Bexar County, and the Texas Department of Transportation (TxDOT San Antonio District). Depending on roadway ownership and access conditions, some projects require coordination with more than one agency.
For low-impact developments, some agencies may accept a Technical Memorandum or abbreviated traffic analysis instead of a full Traffic Impact Analysis. Acceptance depends on trip generation levels, access conditions, and agency discretion.
TxDOT review is typically required when a project accesses or impacts a state highway, frontage road, interchange ramp, or other TxDOT-maintained facility. Even when a city or county is the primary reviewer, TxDOT coordination may still be required.
Timeframes vary based on study complexity and agency review cycles. An initial applicability review may take only a few days, while a full Traffic Impact Analysis typically takes several weeks, including agency comments and revisions.
Typical inputs include a site plan, proposed land use details, anticipated opening year, and access locations. Civotec can assist early in the process by preparing trip generation estimates and identifying required data.
In some cases, reviewing agencies may accept a previously approved Traffic Impact Study if conditions have not materially changed. Acceptance is agency-specific and usually requires confirmation through coordination.
If deficiencies are identified, the study will recommend mitigation measures such as turn lanes, signal timing adjustments, access modifications, or other improvements needed for agency approval.
Yes. Civotec coordinates directly with cities, counties, and TxDOT throughout the Traffic Impact Analysis process, including scope confirmation, submittals, and responses to agency comments.
Costs vary depending on project size, study complexity, and agency requirements. A small technical memorandum or applicability review typically costs less than a full Traffic Impact Analysis. For a project-specific cost estimate, contact info@civotec.com
When a Traffic Impact Analysis Is NOT Required in San Antonio
A Traffic Impact Analysis (TIA) is not required for every development in San Antonio, Texas, or throughout Bexar County. Many smaller projects within the San Antonio metropolitan area generate low traffic volumes or qualify for exemptions under local development regulations. In these cases, the reviewing agency may determine that a full Traffic Impact Study (TIS) is not necessary.
In San Antonio and surrounding municipalities, a Traffic Impact Study may not be required for developments with minimal trip generation, minor tenant finish-outs, changes in land use that result in no net increase in traffic, or projects that fall below established local or regional thresholds. In some situations, the City of San Antonio, Bexar County, or other local jurisdictions may also waive the requirement when an existing or previously approved traffic study sufficiently addresses the proposed development and its roadway impacts.
Because Traffic Impact Analysis requirements in San Antonio vary by jurisdiction, an initial TIA screening is often recommended to confirm whether a study is required by the City of San Antonio, Bexar County, or the Texas Department of Transportation (TxDOT San Antonio District). Early confirmation helps developers avoid unnecessary traffic studies, reduce permitting delays, and minimize unexpected infrastructure or mitigation costs during the San Antonio development review process.
Technical Memorandum vs. Minor vs. Full Traffic Impact Analysis in San Antonio
Traffic study requirements in San Antonio, Texas, and throughout Bexar County vary by jurisdiction, and not all reviewing agencies in the San Antonio region formally define multiple levels of Traffic Impact Analysis (TIA). In many cases, the City of San Antonio, surrounding municipalities, Bexar County, or the TxDOT San Antonio District determine the appropriate level of analysis based on project-specific traffic impacts rather than fixed study categories.
For developments with limited trip generation and localized traffic effects in San Antonio, a Technical Memorandum or other abbreviated traffic analysis is often accepted. These submittals are commonly used for low-impact projects, minor site changes, or developments that do not significantly affect surrounding intersections or roadway operations.
Some agencies in the San Antonio metropolitan area may require a Minor Traffic Study for moderate-impact developments, particularly when a project accesses or impacts TxDOT-maintained roadways, frontage roads, or major arterials. Minor traffic studies typically include a focused review of peak-hour operations, access conditions, and safety considerations, but are narrower in scope than a full Traffic Impact Analysis.
A Full Traffic Impact Analysis (TIA) is generally required in San Antonio when a development exceeds established agency thresholds, impacts multiple intersections, or creates broader operational or safety concerns. Full TIAs evaluate existing and future traffic conditions, trip distribution and assignment, intersection and roadway capacity, and identify required mitigation measures such as turn lanes, signal improvements, or access modifications.
The required traffic study level in San Antonio and Bexar County is ultimately determined by agency policies, roadway jurisdiction, and specific project characteristics. Early coordination with the City of San Antonio, Bexar County, or the TxDOT San Antonio District is strongly recommended to confirm study scope and documentation expectations and to avoid delays during the San Antonio development permitting and review process.
Steps of a Traffic Impact Analysis in San Antonio
A Traffic Impact Analysis (TIA) in San Antonio, Texas is typically completed in two primary steps. The first step focuses on determining whether a full or minor Traffic Impact Analysis is required based on local agency criteria and project characteristics. If a study is required, the second step involves completing a Traffic Impact Analysis in accordance with the standards and review procedures of the City of San Antonio, Bexar County, or the TxDOT San Antonio District.
Step 1: Initial Traffic Impact Review (TIA Applicability in San Antonio)
The first step of a San Antonio Traffic Impact Analysis evaluates whether a development triggers a formal traffic study requirement.
- Preliminary review of San Antonio TIA requirements: Applicable Traffic Impact Analysis criteria are reviewed based on project location to identify the governing agency—such as the City of San Antonio, Bexar County, or TxDOT—and any applicable thresholds.
- Initial trip generation assessment: Site-generated traffic is estimated using accepted methodologies, including the ITE Trip Generation Manual, to evaluate the potential traffic impacts of the proposed development within the San Antonio roadway network.
- Determination of required study level: Based on trip generation and agency criteria, it is determined whether a limited traffic memorandum is sufficient or if a minor or full Traffic Impact Analysis (TIA) is required for the San Antonio project.
- Coordination with the reviewing agency (as needed): When clarification is required, coordination with the reviewing agency is performed to confirm Traffic Impact Analysis scope, documentation requirements, and study expectations early in the San Antonio development process.
Step 2: Full Traffic Impact Analysis (If Required in San Antonio)
If a full Traffic Impact Analysis is required in San Antonio or Bexar County, the following steps are typically completed.
- TIA scoping and contracting: The Traffic Impact Analysis scope, study limits, and analysis requirements are defined based on agency standards and project characteristics applicable in the San Antonio region.
- Traffic data collection: Traffic volume counts and operational data are collected at study intersections and roadways to support the San Antonio Traffic Impact Analysis.
- Traffic analysis and TIA report preparation: Existing and future traffic conditions are analyzed, and a Traffic Impact Analysis report is prepared in accordance with City of San Antonio, Bexar County, or TxDOT San Antonio District guidelines.
- Agency submittal and review: The completed Traffic Impact Analysis is submitted to the reviewing agency, and the formal San Antonio traffic review process is initiated.
- Agency comments and responses: Agency review comments are addressed, and the Traffic Impact Analysis is revised as required to obtain approval and support project permitting in San Antonio.
Disclaimer
The information provided on this page is intended as a general overview of Traffic Impact Analysis requirements. Requirements, thresholds, and procedures may vary by jurisdiction, project characteristics, and over time. This content should not be relied upon as a substitute for official agency guidelines or direct coordination with the reviewing authority. Final study requirements are determined by the applicable reviewing agency.
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