Virginia
Traffic Impact Study
A traffic engineer estimates trips from your project and their effect on nearby roads, as required for many approvals.
What the work involves
A traffic impact study (TIS or TIA) estimates trips a development will generate, commonly using ITE Trip Generation data, counts existing traffic, analyzes intersection level of service and queues, and recommends turn lanes, signals or other mitigation. Local codes usually set a trip threshold that triggers a study. The study is prepared by a professional engineer experienced in traffic engineering.
Local conditions we plan for
- Coastal flooding, land subsidence and sea level rise in Hampton Roads
- Hurricanes
- Karst in the Shenandoah Valley
- Expansive marine clays in Northern Virginia
Building code: 2021 IBC/IRC adopted at the state level (ICC adoption chart, April 2026).
When you need it
- Development exceeds the local peak hour trip threshold
- New access onto a state highway
- Rezoning or special use permit with traffic concerns
- Agency requests mitigation analysis
Frequently asked questions
How much does traffic Impact Study cost?
Across the US, traffic Impact Study usually costs $5,000 to $100,000 per study. City of Pleasanton staff reports describe a range of $5,000 to $100,000 with most around $30,000; an industry source cites roughly $10,000 to $30,000 for typical development studies. Simple trip generation letters cost less.
How long does traffic Impact Study take?
Plan on 3 to 10 weeks, depending on count timing and agency review from signed proposal to stamped deliverables, longer if a site visit, soil testing or a permit review cycle is involved.
Do I need a licensed PE for traffic Impact Study?
In most US jurisdictions, yes. When the work needs a permit, the plans, calculations or report usually must be sealed by a Professional Engineer licensed in the state where the project is located. Every deliverable we issue for permit is sealed that way.
How do I verify an engineer's license in Virginia?
Engineers practicing in Virginia are licensed by the Board for Architects, Professional Engineers, Land Surveyors, Certified Interior Designers and Landscape Architects (APELSCIDLA). You can confirm a license number and its status in the board's public license search before you sign a contract.
Which building code applies in Virginia?
2021 IBC/IRC adopted at the state level (ICC adoption chart, April 2026). Cities and counties can add local amendments, which is one reason to hire an engineer who works in your area.
What site problems do engineers see most in Virginia?
Common issues include coastal flooding, land subsidence and sea level rise in Hampton Roads, hurricanes, karst in the Shenandoah Valley and expansive marine clays in Northern Virginia.