Using Conditional Probability to Find Driver Age Effect in Crashes

Conditional probabilities were used to explore the potential relationships between driver age and factors related to crash involvement including crash location, manner of collision, roadway character, speed of vehicles prior to crash, roadway surface conditions, and light conditions. The analysis indicated that young and old age groups are usually overinvolved in crashes. While young drivers tend to drive in situations or conditions that increase their risk, elderly drivers tend to avoid adverse conditions, presumably in an attempt to compensate for the decline in their driving capabilities. The results show that young drivers are overinvolved in crashes that are related to speeding, crashes on roadway curves, crashes that resulted in an overturn, head-on, or ran-off-road collision, crashes on weekends, and crashes at night. Older drivers tend to avoid bad weather or adverse driving conditions, and therefore their crashes tend to be in clear weather and during daylight settings. Regardless of the crash location, it was concluded from the analysis of the data that elderly drivers are overinvolved in right turn, left turn, and angle collisions.