Traffic Impact Analysis Regulations (24VAC30-155)

• 24VAC30-155-40.A – Rezoning Proposal Submittals: The regulation currently requires the determination of whether a traffic impact analysis is required to be based on the ITE Trip Generation Manual, 8th Edition. Given that this edition predates significant changes in travel behavior, including those occurring since the COVID-19 pandemic, consideration should be given to revising the regulation to reference the current edition of the ITE Trip Generation Manual rather than a specific edition. This would allow the regulations to remain aligned with contemporary transportation patterns and industry practices.
• 24VAC30-155-40.A – Trip Generation Reductions: Consideration should be given to allowing trip generation reductions when making a TIA determination where enforceable proffered commitments establish specific mode split, internal capture, or other trip-reduction measures. The current requirements can result in disproportionately conservative estimates for developments located near high-capacity transit, where actual vehicular travel demand will be substantially lower than comparable development in locations without transit access.
• 24VAC30-155-40.D – Study Acceptance and Completion: Additional clarity is needed regarding the point at which a TIA is considered accepted, approved, or final. In some instances, review cycles can continue even when a study is technically sound and satisfies VDOT submission requirements because of differing perspectives regarding proposed mitigation measures. Establishing clearer standards for completion would provide greater predictability for applicants, localities, and reviewers.
• 24VAC30-155-60 – Traffic Count Requirements: The table of TIS elements states peak hour of generator counts “Collected daily and peak hour of the generator traffic volumes, tabulated and presented on diagrams with counts provided in an appendix.” But the text says commuter peak hours “The count data shall include, at a minimum, weekday 24-hour counts, and directional turning movement counts during AM and PM peak times of the day.”  The table should be made consistent with practice.
• 24VAC30-155-60.D.2 – Trip Generation: Current requirements to use the higher of the ITE average trip generation rate or fitted-curve equation, together with restrictions on internal capture reductions, can produce highly conservative traffic forecasts. Consideration should be given to allowing greater professional judgment and flexibility where supported by appropriate data and methodology. More representative trip generation estimates would reduce the potential for unnecessary roadway capacity improvements.
• 24VAC30-155-60.D.6 – Background Traffic Projections: The regulations require inclusion of approved but unbuilt developments pursuant to 24VAC30-155-60.D.7 while also requiring application of a background traffic growth rate. Applying both assumptions can result in double-counting of future traffic growth and substantial overestimation of future traffic volumes. This concern is particularly relevant on constrained roadway networks, on roadways with stable or historically declining traffic volumes, and when evaluating long-range Comprehensive Plan horizons. Consideration should be given to providing greater flexibility in determining appropriate background growth assumptions based on documented local conditions.
• 24VAC30-155-60.D.11 – Signal Warrant Analysis: The regulation currently references the Standards for Use of Traffic Control Devices to Classify, Designate, Regulate, and Mark State Highways (24VAC30-315) or the 1998 ITE Manual of Traffic Signal Design. With the adoption of the Virginia Manual on Uniform Traffic Control Devices (VMUTCD), this provision should be updated to clearly identify the applicable current standard for conducting signal warrant analyses.
• 24VAC30-155-60.D.12 – Recommended Improvements: The regulation requires recommended improvements to be developed in accordance with the geometric standards contained in the 2011 VDOT Road Design Manual. VDOT's current Road Design Manual has been updated substantially since that time, and the referenced 2011 version is no longer readily available. The regulation should therefore be revised to reference the current edition of the VDOT Road Design Manual, allowing the requirement to remain consistent with current design standards.
• 24VAC30-155-80 – Fees: Modernizing the fee-payment process to permit electronic payments of TIA revie fees would improve administrative efficiency and simplify the submission process for both applicants and VDOT staff.

General Traffic Impact Analysis Process Feedback

• Opportunities for Direct Coordination: Providing greater opportunities for applicants and consultants to meet directly with VDOT staff, preferably in person, would improve communication and may reduce unnecessary review cycles.
  • Clarification-Based Comments: Many TIA comments seek clarification rather than identify substantive technical issues and could be resolved through brief coordination before formal comments are issued.
  • Efficient Issue Resolution: Short coordination meetings could resolve questions more efficiently than multiple rounds of written comments, helping reduce approval timelines.
• Consistency of TIA Reviews: Greater statewide consistency in the review of TIAs would benefit applicants, localities, and VDOT staff. Current expectations regarding the type and level of information required can vary among offices and individual reviewers. Establishing more uniform review standards and guidance would improve predictability and reduce unnecessary revisions.
• Uniform Submission and Tracking Process: TIA submission and review tracking processes vary among jurisdictions and VDOT offices. Establishing a consistent statewide platform or process for submissions, review timelines, comments, and responses would improve transparency and administrative efficiency.
• Focus on Material Review Comments: Review comments should, to the greatest extent practicable, focus on issues that materially affect study findings, operational results, safety conclusions, or recommended improvements. Significant applicant and reviewer resources can otherwise be expended addressing minor items that do not affect the ultimate analysis or recommendations.
• Evaluation of Innovative Intersection Treatments: Applicants are often asked to evaluate innovative or alternative intersection configurations where there is no clear or practical path to implementation or approval. Examples may include roundabouts on high-speed primary arterials or alternative intersection designs that present significant geometric constraints. Requiring detailed analysis of alternatives that are unlikely to be feasible can add considerable time and cost without materially advancing the application or design process.  Preliminary feasibility screening should occur before applicants are required to conduct detailed analysis.
• Turn Lane Warrant Analyses: Greater clarity and consistency are needed regarding the application of turn lane warrant criteria. In some cases, turn lanes are required even when projected traffic volumes are below established warrant thresholds and there is no documented history of safety concerns.
• Signal Warrant Thresholds: Signal warrant analyses should consistently apply the appropriate thresholds based on roadway operating conditions and applicable VMUTCD criteria. Current practice in some instances applies low-speed thresholds regardless of the prevailing roadway speed environment, which can affect the outcome of the warrant analysis. Clear statewide guidance would help ensure consistent application of the appropriate standards.
• VDOT Involvement in Studies Outside Chapter 527: Additional guidance would be beneficial regarding VDOT's role in reviewing traffic studies that do not fall within the Chapter 527 regulatory requirements.
  • VDOT and Local Approval Authority: Clearer delineation is needed between the scope of VDOT's technical review authority and the land-use and development approval authority of local jurisdictions.
  • Reliance on Local Planning Documents: VDOT reviews should recognize and appropriately rely upon locally adopted Comprehensive Plans, transportation plans that are designed to VDOT standards, local ordinances, and other approved planning documents. VDOT's review should primarily focus on technical transportation considerations and recommendations within its jurisdiction rather than duplicating or superseding local land-use approval processes.