A Guide to Navigating Existing and Emerging Sources of Local Vehicle-Miles-Traveled (VMT) and Travel Data

Since California passed SB 375, reducing greenhouse gas emissions from transportation sector is critical for California to meet its climate goals. The existing regional planning framework by Metropolitan Planning Organizations (MPOs) has been strengthen by the bill. MPOs develop Sustainable Communities Strategies (SCS) and conduct Regional Housing Need Allocations (RHNA) to coordinate land use and transportation planning across levels of governments. Particularly, local governments have played the key role in exercising their land use planning and approval authority to reduce motor vehicle trips. While local governments tend to depend on MPOs to access VMT and travel data, some local jurisdictions have collected their own travel data for their own local planning needs. Additionally, with advances in technologies such as big data and artificial intelligence (AI), new sources of travel data are rapidly emerging. As local jurisdictions’ role become more critical to meeting the State’s emission targets, the availability of reliable and accurate local VMT and travel data become increasingly important to assess the success of various land use/transportation strategies in achieving the greenhouse gas emission reduction goals. In this context, we aim to answer three questions in this study. 

• How have local jurisdictions dealt with local VMT needs so far and what are the challenges experienced in doing so?
• What are the existing and emerging public/private sources of VMT and travel datasets/tools that could help local jurisdictions develop local VMT and emission estimates? 
• How could local jurisdictions in various sizes/capabilities choose the best source of data for their planning activities?

We will develop a comprehensive list of currently available VMT and travel datasets by conducting an extensive and thorough literature review that covers academic papers and technical reports. First, we aim to understand the state-of-the-practice of local jurisdictions and MPOs with and demand for VMT and travel data through surveys and interviews. We will design a survey that target all local governments and MPOs in California. The survey will primarily ask questions about a) the types and extents of VMT and travel data that the local governments/MPOs need, b) their practices that require such data, and c) gaps/challenges of the current data they use. The survey results will allow us to identify best practices on how local governments/MPOs have used such data. Second, we will reach out to at least 10 local governments and 4 MPOs (one from Southern California, Central Valley, Central Coast, and Northern California regions) that are representative of the various regions statewide to conduct interviews. The intent is to get best practices that are applicable for a given region. Through the interviews, various issues with such data will be discussed in detail including potential limitations, concerns and biases, technical challenges, etc.

Once the dataset list is finalized, we will collect the datasets for selected cities as a geographical boundary. We will evaluate the collected datasets by analyzing them with various evaluation criteria, such as comprehensiveness, representativeness, accuracy, cost, other quality measures. The evaluation results will be summarized into a guidebook that will support local governments’ decision on selecting datasets/tools that would best suit their need given their constraints. .