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Serious Injury Assessment in Traffic Crash Investigation and Reporting


The National Highway Traffic Safety Administration (NHTSA) reports that in 2012, 33,561 people were fatally injured in the estimated 5,615,000 law enforcement reported motor vehicle traffic crashes; 2,362,000 people were injured; and 3,950,000 crashes resulted in property damage only.

Law enforcement agencies are responsible in the United States for investigating and reporting on motor vehicle crashes. Small numbers of specially trained law enforcement officers within some agencies have achieved a high level of expertise in investigating and reporting motor vehicle crashes that involve fatalities. To report that information nationally, the NHTSA houses extremely accurate and credible nationwide census data on all traffic fatalities that have occurred on public roads over the last five decades. The NHTSA Fatality Analysis Reporting System (FARS) funds analysts in every State to conduct quality control on fatal crash investigations, which then undergo further analysis by the NHTSA National Center for Statistics and Analysis (NCSA) before publication in the FARS data tables, which are made publicly available.

Injury crashes, however, do not undergo such scrutiny, are not normally investigated by officers specially trained in crash reconstruction, and the levels of injuries suffered by persons involved in crashes are usually determined by law enforcement officers at the crash scene. Some injury reporting may involve consultation with medical professionals before rendering the assessment, but in most cases injury severity is classified by the law enforcement officer based on his/her own knowledge, training and experience. Several studies have shown that the level of injury assessments made by law enforcement officers when compared to actual diagnoses by medical professionals results in some significant error.

*These errors can cause significant issues for the nation’s surface transportation system. State Departments of Transportation and highway safety offices must efficiently allocate limited resources to identify and remediate safety problems on the nation’s highways. Transportation professionals rely heavily on both fatality and serious injury data to identify locations and issues of concern in order to increase highway safety performance. *

*The Moving Ahead for Progress in the 21st Century (MAP-21) requires a performance-based framework to tell a national story about the performance of the nation’s roads. MAP-21 establishes performance areas for safety that include performance measures for the numbers and rates of fatalities and serious injuries. States must set targets that reflect these performance measures, and in the case of the Federal Highway Administration’s (FHWA) Highway Safety Improvement Program (HSIP), failure to achieve these targets will result in specific requirements the state must undertake until targets are achieved. The NHTSA, in collaboration with the Governor’s Highway Safety Association (GHSA), are required to set targets against 11 safety outcome performance measures that also include the number of serious injuries. *

The FHWA, NHTSA and GHSA all recognize that serious injury reporting is inconsistent and the data is often incomplete. As mentioned, serious injury crash data is often underreported or misreported, recorded subjectively and inconsistently at the crash scene, may be misrepresented in state crash or health datasets. This means the data may not be collected, reported, recorded, tracked, or utilized consistently across states.


The objective of this research is to build on previous research in determining the accuracy of law enforcement traffic crash reporting with respect to injury codes to develop information, remedial training and educational materials that will enable law enforcement officers to make better, informed assessments of the severity of injury as a result of traffic crashes.


The evaluation of the accuracy of law enforcement assessments of the level of serious injury in crash reports and the development of informational and training materials to improve these assessments is extremely urgent. MAP-21 requires that States use performance measures and set targets against serious injuries. Furthermore, MAP-21 establishes a National goal to reduce serious injuries and fatalities on all public roads. It is important that the data reported be accurate and tells a national story.

The payoff potential is huge. Accurate data will lead to improved implementation of safety countermeasures and enable State to better support the National goal of reducing fatalities and serious injuries on the Nation’s roads.

Depending on the level of error and the likelihood that the quality of level of injury assessments will improve, could weigh heavily on national and State decisions to more quickly implement data linkage systems that will link crash data to the medical professionals assessment of level of injury. As noted, this system will vastly improve the quality and accuracy of crash data.

Related Research:

Several projects and initiatives are underway to attempt to mitigate serious injury reporting error issues, including:


*The NHTSA initiated the Crash Outcome Data Evaluation System (CODES) in 1992. CODES uses linked electronic data to track persons involved in motor vehicle crashes from the scene, and, if injured, through the health care system to a final destination. Simply, the law enforcement crash report is linked to medical records reports so that the level of injury assessment is conducted by a medical professional, not a law enforcement officer. In theory, the use of probabilistic data matching techniques would make it possible to work with large statewide data files that include all persons involved in a crash. Thus, sufficient records linked to outcome information are generated to determine statistically which highway safety counter measures are most effective for reducing injuries and deaths from motor vehicle crashes. With this information, NHTSA, the states, and other highway safety stakeholders can target resources where they will have the most impact on reducing mortality, morbidity, injury severity and health care costs. However, CODES has not been instituted in all states and funding for the program was terminated in 2013, requiring states to continue CODES programs independently. Additionally, most states in the program used CODES for specific research topics and did not report all injury crashes through the system. Thirty-four states participated in CODES at some level. That number has been significantly reduced after funding for the program was terminated. *


*_The NHTSA currently estimates the number of serious injury crashes nationwide through its National Automotive Sampling System (NASS) and the General Estimates System (GES). More specifically, GES data come from a nationally representative sample of police reported motor vehicle crashes of all types, from minor to fatal. The system began in 1988, and was created to identify traffic safety problem areas, provide a basis for regulatory and consumer initiatives, and form the basis for cost and benefit analysis of traffic safety initiatives. The information is used to estimate how many crashes of different kinds take place, and what happens when they occur. _*


**The National Cooperative Highway Research Program (NCHRP) project 20-24 (37)K - Measuring Performance among State DOTs: Sharing Good Practices -- Serious Crash Injury - charts a path forward on collecting serious injury crash data for state DOT performance measurement and management. This projects will help build the capacity of state DOTs and other agencies for expected performance management requirements embedded in MAP-21 and are being pursued by both individual states and national organizations.


**NCHRP project 17-57: Development of a Comprehensive Approach for Serious Traffic Crash Injury Measurement and Reporting Systems, which seeks to develop a roadmap to assist States in developing and implementing an interim system to measure and report injury severity through Data Linkage. The research team will develop and describe possible implementation options for selecting the correct level of injury assessment used by medical professions to implement data linkage for roadway crashes. This project is still underway.


*_Finally, the FHWA is issuing regulations to carry out the performance-based requirements in MAP-21. The FHWA issued a Notice of Proposed Rulemaking (NPRM) in March of 2014, in which it proposed that all law enforcement agencies that report on traffic crashes adopt the coding conventions, definitions and attributes recommended by the Model Minimum Uniform Crash Criteria (MMUCC). MMUCC is the recommended standard for the data elements included in a crash report. Many States and local jurisdiction do not comply with the MMUCC recommendations, especially when defining and reporting on serious injuries. If adopted in final regulations, this requirement would establish a uniform basis under which law enforcement agencies would determine and report on serious injuries. _*


Safety advocates, law enforcement agencies, traffic crash report data users

Sponsoring Committee:ANB40, Traffic Law Enforcement
Research Period:24 - 36 months
Research Priority:Medium
RNS Developer:Keith Williams
Source Info:1. NCHRP, Measuring Performance Among State Dots: Sharing Good Practices -- Serious Crash Injury, September 2013, http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3148
2. Burdett, Beau et al, Accuracy of Injury Severity Ratings on Police Crash Reports, University of Wisconsin, trid.trb.org/view.aspx?id=1338741
3. Popkin, C. L., B. J. Campbell, A. R. Hansen, and J. R. Stewart. Analysis of the Accuracy of 584 the Existing KABCO Injury Scale. University of North Carolina Highway Safety Research 585 Center, Chapel Hill, NC. 1991.
4. Farmer, C. M. Reliability of Police-Reported Information Determining Crash and Injury Severity. Traffic Injury Prevention, Vol. 4, No. 1, 2003, pp.38-44.
5. Tarko, A. P., H. Bar-Gera, J. Thomaz, and A. Issariyanukula. (2010). Model-Based Application of Abbreviated Injury Scale to Police-Reported Crash Injuries. In Transportation Research Record: Journal of the Transportation Research Board, No. 148, Transportation Research Board of the National Academies, Washington, D.C., 2010, pp.59-68.
6. Tsui, K. L., F. L. Soa, N. N. Sze, S. C. Wong, and T. F. Leung. Misclassification of Injury Severity Among Road Casualties in Police Reports. Accident Analysis and Prevention, Vol. 41, Nov. 1, 2009, pp. 84-49.
Date Posted:01/04/2016
Date Modified:03/09/2016
Index Terms:Crash injuries, Injury severity, Crash investigation, Crash reports,
Cosponsoring Committees: 
Pedestrians and Bicyclists
Data and Information Technology
Safety and Human Factors

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