Traffic Impact Study and Analysis Requirements in Louisiana
What Is a Traffic Impact Analysis and Why Is It Important in Louisiana?
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. In Louisiana, a TIA 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.
Across major Louisiana metropolitan areas, Traffic Impact Studies are commonly required by reviewing agencies such as municipal engineering or planning departments, parish governments, metropolitan planning organizations, and the Louisiana Department of Transportation and Development (LADOTD). These studies are typically triggered when a development exceeds defined trip generation levels, affects roadway access, or meets specific size or land-use criteria established by local or state agencies. In practice, requirements are most frequently encountered in areas such as Baton Rouge, New Orleans, Lake Charles, Lafayette, and Shreveport, where development activity, state highways, and regional travel patterns create a greater need for structured traffic review.
The purpose of a Traffic Impact Study in Louisiana is not only to quantify traffic impacts, but also to identify appropriate mitigation measures, such as intersection improvements, signal timing adjustments, access management modifications, or additional turn lanes, to maintain acceptable traffic operations and safety. A well-prepared Traffic Impact Study supports informed permitting and access decisions by local governments and LADOTD, helping development projects move forward without creating congestion, safety concerns, or operational deficiencies. For developers working anywhere in Louisiana, completing a Traffic Impact Study early in the project lifecycle reduces the risk of review delays, design changes, or unexpected infrastructure costs during agency coordination.
Which Agency Reviews Your Development in Louisiana?
The agency responsible for reviewing a Traffic Impact Study (TIS) in Louisiana depends on the project location, roadway ownership, and site access conditions. Across Louisiana’s major metropolitan areas, this determination is typically made by confirming municipal boundaries, parish jurisdiction, and whether the proposed development connects to a LADOTD-maintained roadway. Identifying the correct reviewing agency early is an important step in the Louisiana Traffic Impact Analysis (TIA) process and can help reduce delays during permitting and development review.
The appropriate reviewing agency for a Traffic Impact Analysis in Louisiana can usually be identified using the following steps:
- Confirm whether the site is within an incorporated city: If the project is located within the corporate limits of a city such as Baton Rouge, New Orleans, Lake Charles, Lafayette, or Shreveport, that municipality is typically the primary reviewing authority for the Traffic Impact Analysis through its planning, engineering, or public works department.
- Check if the site is outside city limits but within parish jurisdiction: Developments located outside incorporated city boundaries are generally reviewed by the applicable parish government, such as East Baton Rouge Parish, Jefferson Parish, Calcasieu Parish, Lafayette Parish, or Caddo Parish, depending on project location and roadway ownership.
- Determine whether the development impacts a state roadway: If site access is provided from a state highway, frontage road, interchange ramp, or any facility maintained by the Louisiana Department of Transportation and Development (LADOTD), LADOTD review is typically required, either as the primary reviewing agency or in coordination with the city or parish.
- Identify overlapping or joint jurisdiction cases: Some developments in Louisiana require coordination between multiple agencies, such as a city and LADOTD or a parish and LADOTD, depending on roadway jurisdiction, access location, and the scale of projected traffic impacts.
- Confirm Traffic Impact Analysis requirements through agency coordination when needed: For projects near municipal or parish boundaries, within planning districts, or involving complex access conditions, direct coordination with the reviewing agency is commonly used to confirm Louisiana TIA requirements, study scope, and documentation expectations.
Traffic Impact Analysis Requirement per Agency
| Agency or Jurisdiction | TIA Threshold | Notes |
|---|---|---|
| Louisiana DOTD | ≥100 peak-hour trips (peak direction) on state highways (or within ¼ mile) | Pre-application meeting with district traffic operations engineer; waiver possible in marginal cases. PE seal required; mitigation may be required for driveway permits. |
| City of New Orleans | Case-specific | No numeric trip threshold published; CPC may require TIA for major/special approvals. Scope coordinated with DPW and CPC. |
| City of Baton Rouge / East Baton Rouge Parish | Case-specific | No explicit published TIA trigger found; traffic requirements may be set based on anticipated generation/circulation. Projects near state highways often follow DOTD criteria. |
| City of Lafayette / Lafayette Parish (LCG) | ≥100 vehicles/hour | TIA required for certain entitlements/development meeting the 100 vehicles/hour trigger; focused analysis may also be required for safety/congestion. Coordinate scoping with Public Works; DOTD coordination if near a state highway. |
| City of Shreveport / Caddo Parish | Case-specific | No published numeric trigger found in available materials; often relies on DOTD criteria when state highways are involved. Requirement typically set via city/MPC/DOTD coordination. |
| Calcasieu Parish (Lake Charles area) | >1,000 daily trips | Submit parish TIA worksheet and attend scoping meeting; analysis level depends on impact magnitude. PE-prepared study; mitigation/ROW dedication may be required. |
| Houma / Terrebonne Parish | Retail >25,000 sf | Trigger is size-based (not trip-based); confirm current practice with parish staff due to age of cited ordinance. Study typically includes trip generation, capacity, access/parking, and mitigation recommendations. |
| Jefferson Parish | Case-specific | TIA may be required depending on project; no numeric threshold published. If within ¼ mile of a state highway, DOTD compliance/coordination is typically required. |
| St. Tammany Parish | Varies by land use (units/acres/sf); Drive-through: always | Threshold-based triggers by use; parish engineer can still require TIA based on congestion/growth conditions. PE/AICP-prepared study reviewed by parish. |
| Ascension Parish | All developments (except single-family); <40 vs ≥40 peak-hour trips controls scope | TIA required for subdivisions/developments needing permits (except individual single-family); Threshold 1 (<40) limited submittal, Threshold 2 (≥40) full TIA. Parish-selected independent contractor prepares TIA; applicant pays and attends scoping. |
| St. John the Baptist Parish | Case-specific | No published numeric trigger found; planning documents suggest broad applicability for subdivisions/development. Expect DOTD coordination near state highways and be ready to provide trip generation data. |
Questions and Answers About Traffic Impact Analysis in Louisiana
There is no technical difference. The terms Traffic Impact Study and Traffic Impact Analysis are used interchangeably by reviewing agencies in Louisiana to describe the same traffic evaluation process.
Traffic Impact Analysis 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 city planning or engineering departments in major areas such as Baton Rouge, New Orleans, Lake Charles, Lafayette, and Shreveport, the applicable parish government, and the Louisiana Department of Transportation and Development (LADOTD). Depending on roadway ownership and access conditions, some projects require coordination with more than one agency.
For low impact developments, some agencies in Louisiana 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.
LADOTD review is typically required when a project accesses or impacts a state highway, frontage road, interchange ramp, or other LADOTD maintained facility. Even when a city or parish is the primary reviewer, LADOTD 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 Louisiana development process by preparing trip generation estimates and identifying required data.
In some cases, reviewing agencies may accept a previously approved Traffic Impact Study if site conditions, land use, or traffic patterns have not materially changed. Acceptance is agency specific and usually requires confirmation through coordination.
If deficiencies are identified, the Traffic Impact Analysis 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, parishes, and LADOTD throughout the Traffic Impact Analysis process, including scope confirmation, agency submittals, and responses to review 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 Louisiana
A Traffic Impact Analysis (TIA) is not required for every development in Louisiana. Many smaller projects across the state generate low traffic volumes or qualify for exemptions under local or parish development regulations. In these cases, the reviewing agency may determine that a full Traffic Impact Study (TIS) is not necessary.
In Louisiana’s major metropolitan areas, including Baton Rouge, New Orleans, Lake Charles, Lafayette, and Shreveport, 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, parish, or regional thresholds. In some situations, a city, parish, or the Louisiana Department of Transportation and Development (LADOTD) may also waive the requirement when an existing or previously approved traffic study adequately addresses the proposed development and its roadway impacts.
Because Traffic Impact Analysis requirements in Louisiana vary by jurisdiction, an initial TIA screening is often recommended to confirm whether a study is required by the applicable city, parish, or LADOTD. Early confirmation helps developers avoid unnecessary traffic studies, reduce permitting delays, and minimize unexpected infrastructure or mitigation costs during the Louisiana development review process.
Technical Memorandum vs. Minor vs. Full Traffic Impact Analysis in Louisiana
Traffic study requirements in Louisiana vary by city, parish, and roadway jurisdiction, and not all reviewing agencies formally define multiple levels of Traffic Impact Analysis (TIA). In many cases, the appropriate level of analysis is determined by the reviewing authority, such as a municipal engineering department, parish government, or the Louisiana Department of Transportation and Development (LADOTD), based on project specific traffic impacts rather than fixed study categories.
For developments with limited trip generation and localized traffic effects in Louisiana, 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 nearby intersections or roadway operations. This approach is frequently seen in smaller developments in areas such as Baton Rouge, Lake Charles, Lafayette, or Shreveport.
Some agencies in Louisiana may require a Minor Traffic Study for moderate impact developments, particularly when a project accesses or affects LADOTD maintained roadways, frontage roads, or major state routes. 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 Louisiana when a development exceeds established local or state thresholds, affects 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 necessary mitigation measures such as turn lanes, signal improvements, or access modifications.
The required traffic study level for a Louisiana Traffic Impact Analysis is ultimately determined by agency policies, roadway jurisdiction, and specific project characteristics. Early coordination with the applicable city, parish, or LADOTD is strongly recommended to confirm study scope and documentation expectations and to avoid delays during the Louisiana development permitting and review process.
Steps of a Traffic Impact Analysis in Louisiana
A Traffic Impact Analysis (TIA) in Louisiana 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, parish, or state criteria and the specific characteristics of the proposed development. If a study is required, the second step involves completing a Traffic Impact Analysis in accordance with the standards and review procedures of the applicable city, parish, or the Louisiana Department of Transportation and Development (LADOTD).
Step 1: Initial Traffic Impact Review (TIA Applicability in Louisiana)
The first step of a Louisiana Traffic Impact Analysis evaluates whether a development triggers a formal traffic study requirement.
- Preliminary review of Louisiana TIA requirements: Applicable Traffic Impact Analysis criteria are reviewed based on project location to identify the governing agency, such as a municipal engineering department, parish government, or LADOTD, and to identify 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 on the surrounding roadway network in Louisiana.
- Determination of required study level: Based on trip generation results and agency criteria, it is determined whether a limited traffic memorandum is sufficient or if a minor or full Traffic Impact Analysis is required for the Louisiana 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 Louisiana development review process.
Step 2: Full Traffic Impact Analysis (If Required in Louisiana)
If a full Traffic Impact Analysis is required in Louisiana, 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 relevant city or parish.
- Traffic data collection: Traffic volume counts and operational data are collected at study intersections and roadways to support the Louisiana 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, parish, or LADOTD guidelines.
- Agency submittal and review: The completed Traffic Impact Analysis is submitted to the reviewing agency, and the formal Louisiana 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 Louisiana.
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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