Creating a Data Resource of California Police Stops for Use in Traffic Safety Applications

Traffic stops are one the most common ways in which the American public interacts with police. Although one of the leading reasons given for police traffic stops is a violation of the vehicle code, there is limited and mixed research on the impact of traditional police traffic enforcement on traffic safety outcomes. At present, few large data resources with an appropriate level of detail exist to facilitate investigations of this type. The 2015 Racial and Identity Profiling Act (RIPA) requires all law enforcement agencies in California to collect and submit vehicle (including bicycle) and pedestrian stop data to the State Department of Justice annually, starting no later than 2022. This project will use 2018-2022 confidential RIPA stop data to categorize all police traffic stops using known risk factors for fatal and severe collisions and to create new variables relevant to traffic safety, yielding a standardized statewide data set useful for examining and controlling for police traffic stops as they relate to traffic safety outcomes. Further, the research team will both establish clear guidance for how to process RIPA data efficiently for future data releases and will also will geospatially join the processed RIPA data files with traditional transportation and land use data sources using stop location so that this data resource can be made available to others for future research.

  • Record URL:
  • Supplemental Notes:
    • Full completion of this research requires that we submit a Data Request Application to the California Department of Justice Research Center (DOJRC) requesting access to all available years of Confidential Stop Data for Research Purposes (we expect 2018-2022 files). While we do not anticipate any issues with obtaining the data, the success of this project depends on this data request application being approved by the California DOJRC.


  • English


  • Status: Active
  • Funding: $63669
  • Contract Numbers:


  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Managing Organizations:

    Center for Pedestrian and Bicyclist Safety

    University of New Mexico
    Albuquerque, NM  United States  87131
  • Project Managers:

    Melendrez, Carman

    Stearns, Amy

  • Performing Organizations:

    University of California, Berkeley

    Safe Transportation Research and Education Center
    Berkeley, CA  United States  94720
  • Principal Investigators:

    Griswold, Julia

  • Start Date: 20230601
  • Expected Completion Date: 20240531
  • Actual Completion Date: 0
  • USDOT Program: University Transportation Centers Program

Subject/Index Terms

Filing Info

  • Accession Number: 01890174
  • Record Type: Research project
  • Source Agency: Center for Pedestrian and Bicyclist Safety
  • Contract Numbers: 69A3552348336
  • Files: UTC, RIP
  • Created Date: Aug 17 2023 8:10AM