The Highway Safety Information System (HSIS), established in 1987, is a foundational highway research data system. The State of North Carolina has participated in the HSIS program since 1990, 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 North Carolina HSIS data for the years 2018 and beyond. Data and documentation prior to 2018 (1990-2017) are available upon request to the HSIS Virtual Laboratory. Prior to 2018, the North Carolina datasets included variables for the following files:
 

1. Roadway inventory.
2. Accident characteristics.
3. Vehicles involved in crashes.
4. Vehicle occupants involved in crashes.

The revised North Carolina database incorporated into HSIS contains eight different files:
 

1. Roadway inventory (including traffic information).
2. Traffic signal inventory.
3. Interchange inventory.
4. Horizontal curve inventory.
5. Freeway exit inventory.
6. Crash characteristics.
7. Units involved in crashes.
8. Persons involved in the crash.