Crash Rates and the larger problem at hand
Crash Rates
The safety performance of roadways are almost always reported as rates. That is, some measure of harm (deaths, injuries, or property damage) divided by some indicator of exposure to the risk of this harm. Common rates related to road traffic fatalities include the number of deaths per capita, per registered vehicle, per licensed driver, or per vehicle mile traveled.
Simple counts are almost never used. The annual count of fatalities is a rate, namely, the number of fatalities per year.
There is no one rate that is superior to others in any general sense. (more…)
Traffic Harm
Types of harm
Fatality
Conceptually, the clearest type of harm in a road traffic crash is death – or a fatality. However, the definition of a road-traffic fatality is far more complicated than a casual thought might indicate, and involves many essentially arbitrary criteria. In the United States, for example, the definition used in the Fatality Analysis Reporting System (FARS)[2] run by the NHTSA is a person who dies within 30 days of a crash on a US public road involving a vehicle with an engine, the death being the result of the crash. In America therefore, if a driver has a non-fatal heart attack that leads to a road-traffic crash that causes death, that is a road-traffic fatality. However, if the heart attack causes death prior to the crash, then that is not a road-traffic fatality. (more…)