A traffic impact analysis or traffic report is a study of the potential traffic impacts of a development on the surrounding transportation system. The purpose of the study is to document the impacts and recommend on-site and off-site mitigation for those impacts.
A traffic report is required for any new development, redevelopment or change of use (including tenant improvements).
The applicant will hire a consultant to provide the traffic report. The consultant must be a professional engineer, licensed in Washington. There are two types of traffic reports.
Level-One Traffic Report
Level-One Traffic Reports are required for all new development, redevelopment or change of use projects. Some of the items to be included in the report are:
- Project Narrative
- Existing and Proposed Use
- Existing and Proposed Access Design
- Existing Traffic Standard Nonconformities
- Trip Generation Data
- Existing
- Proposed Project Trips
- Net New Trips
- Sight Distance for Vehicles and Pedestrians
- Other Information, as needed
- Recommendations
- Conclusions
Level-Two Traffic Report
Level-Two Traffic Reports are required for larger, more complex projects. Some of the items to be included in the report are:
- All Level-One Traffic Report Requirements as noted above
- Vicinity Map
- Discussion of internal circulation; may include a queuing analysis and loading plan with turning exhibits
- Concurrency
- Trip Distribution
- Level of Service
- Discussion of pedestrian, bicycle, and transit facilities
- Accident Report Data
- On-site and Off-site Mitigation
- Traffic Management Program