REPORTING THRESHOLDS

Background

State data have limitations because of reporting thresholds. When all crashes are not included in a state's file, any analysis is limited by those which are. For example, when only crashes that result in an injured person are included on a statewide database, the lack of information about the uninjured makes it impossible to measure the downward shift from injured to not injured resulting from the implementation of some safety program or safety measure. When the less serious or no injury cases are excluded, the exclusion results in eliminating some of the highway safety success stories and cases for those not affected (persons who do not use the countermeasure and receive no injury). The same is true if the data include only fatalities or even the most seriously injured, such as those persons treated at trauma centers. Also, when states and different agencies within a state choose different levels of property damage for reporting, the mix of crashes in each state will vary. Police vary in their estimate of damage and, over time, the same repair may cost more because of inflation. Finally, regardless of the threshold levels, sometimes the data collector may find it easier to ignore them and avoid the demands of data collection.

Which Crashes Should Be Reported?

From the point of view of the police collecting crash data, less is better. Police officers are responsible for investigating the crash at the scene and documenting information about the crash, vehicles, and persons involved. Police, understandably, resent expanding the scope of data collection to meet users' needs because the extra data are perceived as not related to police functions and as too time consuming.
From the point of view of the evaluator/user, more is better. Information is needed about all crashes and all persons involved to accurately monitor the status of highway safety. Incomplete data greatly limit the usefulness of the state's crash data as a source of information for supporting highway safety program efforts.

Types of Reporting Thresholds

States have initiated reporting thresholds to balance data collection demands with available staff time and funds. Thresholds focus on the type of roadway (public/private), the level of property damage or vehicle damage, the occurrence of an injury, and/or the absence of an injury. Implementation of these threshold criteria is not uniform among the states.

1. Type of Road: Most states limit reporting to crashes which occur on public roads. Thus, crashes and/or injuries occurring in private driveways or parking lots are not included in these crash files.

2. Property or Vehicle Damage: Most states limit reporting to those crashes that involve $500-$1,000 of property damage and exclude fender benders, perceived as insignificant. Larger states are more likely to choose the higher property damage threshold or even to go beyond property damage to include only those crashes in which at least one vehicle had to be towed away.

3. Occurrence of Injury: Almost all states report crashes that involve an injured person as defined by use of a functional measure (KABCO) that indicates need for help from the scene. Information is collected identifying the person by age, sex, injury severity, position in vehicle, vehicle number and whether the person was using safety equipment (belts, helmets, etc.).

4. Absence of an injury: In an effort to save time and money, some states do not collect data about the uninjured person involved in a motor vehicle crash.

Recommended Minimum Reporting Threshold

As a minimum, states should collect data for motorists, injured and uninjured, and for nonmotorists involved in crashes in which at least one vehicle is disabled by damage severe enough to prevent driving it.

Please send any comments to: muccmail@nhtsa.dot.gov