The California-based origin-destination data addendum to the 2021 Next-Generation National Household Travel Survey (NHTS) covered the state of California and 16 counties in surrounding states. Conducted for the California Department of Transportation, it provided additional information and spatial granularity about people’s movements to, from, and within the areas under study.
Data were collected in two zones: the core area (census blocks in California) and the halo area (16 counties bordering California in Oregon, Nevada, and Arizona). All trips were assigned origin and destination zones, as well as a travel mode, purpose, and distance. Sociodemographic information related to age, income, and gender was also collected. Data records are available in two file types: a shapefile denoting the core and halo areas and a csv file in which each row is a unique combination of each origin-destination zone (excluding trips without a start or end point in California). Visit NREL’s Transportation Secure Data Center for more information about this travel survey.
| Name | Size | Type | Resource Description | History |
|---|---|---|---|---|
| 2021 NextGen NHTS Addendum – Full-year data | 9.9 GB | Archive | Data encompassing the full year of the study, compiled into one file | |
| 2021 NextGen NHTS Addendum – Month-by-month data | 7.5 GB | Archive | Data encompassing the full year of the study, compiled into 12 monthly files | |
| 2021 NextGen NHTS Addendum – Zones | 55.6 MB | Archive | A Shapefile containing all of the zone boundaries used for the study’s trip aggregation | |
| 2021 NextGen NHTS Addendum – Documentation | 3.7 MB | Archive | Documentation for the study |
Data Center, Transportation Secure. 2024. "Data Files for the 2021 Next-Generation National Household Travel Survey – Origin-Destination Data Addendum for the California Region." NREL Data Catalog. Golden, CO: National Renewable Energy Laboratory. Last updated: July 24, 2025.