Investigation-Based Crash Data Studies

The information collected serves to identify and develop safety countermeasures that will reduce the severity of injury and property damage caused by motor vehicle crashes. These Investigation-Based Crash Data Studies -- Crash Investigation Sampling System (CISS), Special Crash Investigations (SCI), and Special Studies (SS) -- involve voluntary information collections through which NHTSA collects detailed data on real world motor vehicle crashes. Specifically, these systems collect data on vehicle safety system performance, occupant injury information including their kinematic interaction with interior components and scene geometry, marking and traffic controls. Respondents are police agencies that collect information on police-reported motor vehicle crashes, employees of tow yards where crashed vehicles are stored, people involved in these crashes, and hospitals with medical records for the people injured in the crash. For the standard investigation-based crash data studies acquisition process, once a crash has been selected for investigation, crash technicians or investigators locate, visit, measure, and photograph the crash scene; locate, inspect, and photograph vehicles; conduct a telephone or personal interview with the involved individuals or surrogate (another person who can provide occupant or crash information, such as parents for minor, or a parent or spouse for decreased individual); and obtain and record crash injury information received from various medical data sources. These information collections support NHTSA’s mission to save lives and prevent injuries due to traffic crashes. The data collected from these systems are used to describe and analyze circumstances, mechanisms, and consequences of serious motor vehicle crashes in the United States. Additionally, these data are used by NHTSA to identify the primary factors related to the source of crashes and their injury outcomes, develop and evaluate effective safety countermeasures, the establishment and enforcement of motor vehicle regulations, that reduce the severity of injury and property damage caused by motor vehicle crashes. On November 15, 2021, the Infrastructure Investment and Jobs Act (Pub. L. 117-58) (IIJA) was signed into law. The Crash Data section (section 24108) of the IIJA authorizes the Secretary of Transportation (NHTSA by delegation) to use funds to enhance the collection of data under CISS by, among other things, including additional data collection sites. As a result of the additional funding provided by the IIJA, in addition to the expansion of data collection from the last modification, NHTSA now plans to phase in 17 additional data collection sites in CISS over the next 3 years. The total data collection sites will incrementally increase from 56 to 73 over the next three years. NHTSA is now accounting for the increases in burden hours for interviewees, police, tow yards and medical facilities for an additional 17 data collection sites. The increase in burden hours and cost for these additional data collection sites are reflected in the Burden to Respondent section of this document. The current approval for Investigation-Based Crash Data Studies collection indicated a total annual 12,063 burden hours; this request increases the total annual burden hours to 17,521. The request for the collection of information is revised due to increasing the number of crashes investigated by Crash Technicians for 2025 and future years for CISS program. The combined impact is an increase of 5,458 total annual burden hours.

The latest form for Investigation-Based Crash Data Studies expires 2029-02-28 and can be found here.

CISS: Interviews with Individuals Involved in Crashes

Federal Enterprise Architecture: Transportation - Ground Transportation

Review document collections for all forms, instructions, and supporting documents - including paper/printable forms.