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Transportation Secure Data Center

Photo of researchers looking at a large, colorful map of the United States.

NREL data experts and engineers analyze large sets of complex transportation data. Housed at NREL, the Transportation Secure Data Center serves as a centralized repository of detailed transportation data from travel surveys and studies conducted across the nation. Photo by Dennis Schroeder, NREL

The Transportation Secure Data Center (TSDC) provides free access to detailed transportation data from a variety of travel surveys and studies. While preserving the privacy of survey participants, this repository makes vital transportation data broadly available to users from the comfort of their own desks via a secure online connection.

Maintained by NREL in partnership with the U.S. Department of Transportation and the U.S. Department of Energy, this centralized repository relieves individual agencies from the burden of fielding numerous data-access requests and provides additional features such as linked reference layers, data filtering, road grade and road network matching, summary statistics, and data set comparisons.

Transportation Data

The TSDC features second-by-second GPS readings for millions of miles of travel, along with vehicle characteristics and survey participant demographics. NREL screens the initial data for quality control, translates each data set into a consistent format, and interprets the data for spatial analysis. NREL processing routines join data points to the road network, link U.S. Census and other spatial data layers, and add information such as road grade.

Cleansed Data Access

Users may quickly access cleansed data from the following studies to support applications that require detailed travel distance and/or speed information, but not detailed latitude and longitude spatial information. Before viewing the data for the first time, you will be required to fill out a short registration form.

In addition, cleansed drive cycle data are available for the studies that included second-by-second GPS vehicle speed profiles.

Spatial Data Access

Users may also access spatial information and other data details through a restricted secure portal environment after completing an application and approval process by filling out these application forms and submitting them via email to The data dictionaries available alongside the downloadable cleansed data sets include information about the variables available in the secure portal environment.

After receiving a log-in account, users may remotely connect to the environment, which prohibits removal of sensitive data. However, the provided software tools and reference data allow users to create specialized database queries, perform detailed calculations, and conduct statistical and geographic information system analyses. Users may also request to have custom files or programs loaded for them, and to have aggregated results or reports sent directly to them.

How to Cite the Data

If you use TSDC data in a publication, please notify us and include a citation in your publication consistent with the following format: "Transportation Secure Data Center." (2015). National Renewable Energy Laboratory. Accessed January 15, 2015:

More Information

The following resources provide more information about the Transportation Secure Data Center:


Contact us to discuss options for joining as a Transportation Secure Data Center partner, to apply for spatial data clearance, or for more information about the project.

Subscribe for periodic email updates when new data sets and features become available in the TSDC.