BACKGROUND INFORMATION ABOUT CRASH DATA

What are Police Crash Reports and What Types of Information Do They Provide?

Motor vehicle crash reports include data collected at the scene of a motor vehicle crash. Crash data describe characteristics of the crash, the vehicles, and the people (drivers, injured and uninjured occupants, and injured non-occupants) involved. They also record the results of a police officer's investigation of the crash. By using evidence found at the scene, and by interviewing participants and witnesses, the investigating officer may answer such questions as:

• "In what directions were the involved vehicles and pedestrians moving prior to impact?"
  

• "What occurred during the impact?" and,
  

• "What factors may have contributed to the crash?"
  

In most states, the data recorded on crash reports are computerized into a central crash data file at the state level.
Statewide motor vehicle crash data systems provide basic information necessary for developing effective highway and traffic safety programs. Data from state crash data systems are used by local, state and federal agencies to:

• identify and prioritize highway and traffic safety problem areas
  

• assess the effectiveness of laws and programs intended to reduce the frequency and severity of motor vehicle crashes and injuries
  

• assess the relationship between vehicle and highway characteristics, crash propensity, and injury severity to support either the development of countermeasures or their evaluation
  

At the Federal level, individual crash reports also provide the basis for national crash information systems, either as the sampling frame or as a source of data. Data from these national systems are utilized in highway safety decision making by agencies at all levels of government.

Why Should Police Crash Data be Standardized?

Crash data lack uniformity between the states and, often, within a state. Similar data elements may have different meanings on different state crash reports, or have the same meanings but have different codings.

Lack of uniform reporting makes the use and comparison of state crash data tenuous or difficult. The use of different elements or definitions within a state can result in inconsistent data and, potentially, incorrect interpretations of data. The same is true when states have different reporting requirements and dissimilar crash data elements -- accurate comparisons are difficult and states can not draw on the experience of other states.

Existing national standards for crash data elements are not uniformly implemented. The Manual on Classification of Motor Vehicle Traffic Accidents, the American National Standards Institute (ANSI) Standard D16.1, was developed to "promote uniformity and comparability of motor vehicle accident statistics." ANSI Standard D20.1, Data Element Dictionary for Traffic Records Systems, was developed to "provide a common set of coding instructions for data elements related to highway safety...."

States periodically revise their crash reporting forms and request information from NHTSA or FHWA. In a recent study conducted by the National Association of Governors' Highway Safety Representatives for NHTSA, eighteen states indicated that they are in the process of revising their crash reporting form, or will revise it, by the year 2000. Many are being spurred to do so by the availability of new technologies such as hand-held computers for data collection. Others are doing so in an effort to reduce the reporting and processing burden on state and local police agencies.

Section 2002(a) of The Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) directed the Secretary  of Transportation to establish a program to establish minimum reporting criteria for a program to ensure national uniform data on deaths and injuries. No such minimum criteria or guidelines currently exist.