Crash Investigation Sampling System
Principal Investigator(s): View help for Principal Investigator(s) United States Department of Transportation. National Highway Traffic Safety Administration
Version: View help for Version V1
| Name | File Type | Size | Last Modified |
|---|---|---|---|
| NHTSA CISS data | 08/29/2025 05:08:PM |
Project Citation:
United States Department of Transportation. National Highway Traffic Safety Administration. Crash Investigation Sampling System. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2025-08-29. https://doi.org/10.3886/E237532V1
Project Description
Project Title:
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Crash Investigation Sampling System
Summary:
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How the Information Is Used
What It Is
The National Highway Traffic Safety Administration has collected crash
data since the early 1970s to support its mission to reduce motor
vehicle crashes, injuries, and deaths on our Nation’s highways. NHTSA’s
crash data collection program consists of the Crash Investigation
Sampling System, the Fatality Analysis Reporting System, the Crash
Report Sampling System, Special Crash Investigations, Non-Traffic
Surveillance, the Crash Injury Research & Engineering Network, and
special studies conducted to address various safety topics. The CISS
builds on the retiring, long running National Automotive Sampling System
Crashworthiness Data System. CISS collects detailed crash data to help
scientists and engineers analyze motor vehicle crashes and injuries.
CISS collects data on a representative sample of minor, serious, and
fatal crashes involving at least one motor vehicle in transport on a
trafficway.
How It Works
After a crash has been sampled, trained Crash
Technicians obtain data from crash sites by documenting scene evidence
such as skid marks, fluid spills, and struck objects. They locate the
vehicles involved, document the crash damage and identify interior
components that were contacted by the occupants. On-site inspections are
followed-up with confidential interviews of the crash victims and a
review of medical records for injuries sustained in the crash. CISS uses
emerging technologies and methods to acquire quality data.
The Crash Technicians are interested only in information that will help them understand the nature and outcome of the crashes.
Personal
information such as names, addresses, license and registration numbers,
and even specific crash locations are not included in public CISS
files.
Sampling
CISS randomly selects thousands of police crash reports at law
enforcement agencies in selected areas across the country. The areas
reflect the geography, population, miles driven, and crashes in the
United States. To be eligible for the CISS sample, a crash must involve
at least one towed passenger vehicle.
Cooperation
CISS depends on the participation and cooperation of law enforcement
agencies, hospitals, physicians, medical examiners, coroners, insurance
companies, salvage facilities, tow yard operators, repair shops, and the
people involved in crashes.
Cooperation from law enforcement agencies enables CISS to list and
select crashes to be studied. Police crash reports – which provide key
information on the location of the crash, the vehicles involved, and
where the injured were taken for medical care – are obtained and treated
as confidential documents. Law enforcement agencies also permit access
to certain roadways and crashed vehicles.
NHTSA is recognized by the Department of Health and Human Services as a
Public Health Authority, allowing the medical community to provide
access to its records. Medical records are the primary source of data on
the nature and severity of injuries.
Tow yards, repair facilities, and impound lots provide access to damaged
vehicles. CISS Crash Technicians photograph vehicles at these sites,
measure vehicle damage, document safety systems, and record the sources
of occupant injury.
Confidential interviews with victims who were involved in crashes
provide crash details, insights into how crashes occur, the extent of
injuries, treatment received, safety system performance, and work time
lost.
Collectively, information from these sources provides a detailed picture
of a crash – from just before the crash through medical care received
by the injured.
How the Information Is Used
The data collected by the CISS field teams is used by NHTSA and others for a variety of purposes:
- Identifying existing and emerging highway safety problems.
- Obtaining detailed crash performance data for passenger vehicles, including the vehicle safety systems and designs.
- Learning more about the nature of crash-related injuries and the relationship between the type and severity of a crash and the resulting injuries.
- Assessing the effectiveness of motor vehicle standards and highway safety programs.
After all personal identifiers are removed, information collected by
CISS is made available to other Federal agencies; state and local
governments; universities; research institutions; automobile, trucking,
and insurance industries; and the general public.
Original Distribution URL:
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https://www.nhtsa.gov/crash-data-systems/crash-investigation-sampling-system
Scope of Project
Geographic Coverage:
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United States
Time Period(s):
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2016 – 2023
Data Type(s):
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aggregate data;
event/transaction data;
survey data
Methodology
Sampling:
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CISS randomly selects thousands of police crash reports at law
enforcement agencies in selected areas across the country. The areas
reflect the geography, population, miles driven, and crashes in the
United States. To be eligible for the CISS sample, a crash must involve
at least one towed passenger vehicle.
Related Publications
Published Versions
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