The Highway Safety Information System (HSIS), established in 1987, is a foundational highway research data system. The State of California has participated in the HSIS program since 1991, providing quality data to HSIS for use by researchers through a request system. In 2021, HSIS began a modernization effort with the goal of expanding the technological and analytic capabilities of the data system. This modernization provides an increased emphasis on spatial analysis and cloud-based data management.

What Has Changed

This guidebook is intended to support the use of California HSIS data for the years 2018 and beyond. Data and documentation prior to 2018 (1991-2017) are available upon request to the HSIS Virtual Laboratory. Prior to 2018, the California datasets included variables for the following files:

1. Roadway inventory.
2. Intersection inventory.
3. Interchange ramp inventory.
4. Accident characteristics.
5. Vehicles involved in crashes.
6. Vehicle occupants involved in crashes.