Transportation Impact Analysis
A transportation impact analysis, or TIA, is a study of the potential transportation 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 TIA is required for any new development, redevelopment or change of use (including tenant improvements).
The application will hire a consultant to provide the TIA. The consultant must be a professional engineer, licensed in Washington state. There are two types of traffic reports. For more information, refer to the TIA Guidelines.
Traffic Modeling
Based on findings from the trip generation estimates for a project, operational modeling may be required. Any project generating 50 or more PM Peak hour vehicle trips will be required to conduct a traffic modeling run and document operations analysis in the TIA. The transportation reviewer also has the discretion to require traffic modeling for any project regardless of the number of PM peak hour trips due to the unique nature of the site, access changes, site-specific conditions, etc. Work with your transportation reviewer for assistance on the Development Review Modeling Request form.