Relevant Research

Some tasks may call for a higher-level evaluation than the performance measures shared in this website can provide or may require the analyst to evaluate performance measures using resources beyond the tools defined in this website. The following research and data repositories provide resources that may be relevant to the analyst.

California Senate Bill 375 - Research on Impacts of Transportation and Land Use-Related Policies

The sponsored a review of existing research to identify the impacts of various government actions on vehicle use and greenhouse gas emissions. Completed in 2014, this work reviews the potential of various transportation and land use strategies to reduce vehicle miles traveled (VMT) by reducing the length of vehicle trips and shifting travel from driving alone to other modes.

The research results are presented in policy briefs and technical background documents, which can be downloaded at:

In addition to providing a high-level understanding of the potential climate impacts of potential investments, this information can be used to evaluate measures related to mode share, specifically:

State Smart Transportation Initiative (SSTI)

New research on the effects of non-motorized accessibility on mode shift is being conducted by the State Smart Transportation Initiative (SSTI), which has been assisting WSDOT on testing the Cube Access tool. SSTI completed an analysis in Hawaii that examines Community Accessibility Measures focusing on pedestrian, bicycle and transit investments.  This study implies a solid link between improved nonmotorized/transit accessibility and vehicle mode shift, although not any specific values.  More recently, SSTI has examined the relationship between zone-based accessibility scores and zone-level mode share from the American Community Survey, conducted a study of accessibility in Virginia, and is looking at changes in VMT relative to accessibility as part of a study in Massachusetts, still in progress. More results should become available to WSDOT in the near future. In the meantime, SSTI’s reports are available from:

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Transit Cooperative Research Program

The Transit Cooperative Research Program, sponsored by the Federal Transit Administration, conducts research on transit-related topics. Their publications can be accessed here:

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National Transportation Library’s Repository & Open Science Access Portal (ROSAP)

The National Transportation Library hosts an open data and research portal that combines resources from multiple Federal transportation agencies. ROSAP can be accessed at:

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WSDOT Library Digital Collections

The WSDOT Library provides extensive print and digital resources, including reference materials for transportation planning and engineering and WSDOT publications. The library’s Digital Collections can be accessed at:

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