Does the occurrence of a few traffic accidents at a particular location mean something should be changed?
Not necessarily. Accidents occur on a regular basis in otherwise perfect conditions, and the State publishes expected accident rates for various types of intersections and roadway segments. The accident rate at an intersection is the number of accidents per million vehicles entering the intersection. When we evaluate the accident history of an intersection, we compare the actual accident rate to the expected accident rate. If the actual rate is significantly and consistently higher (year after year) than the expected rate, then we look at engineering ways of reducing the actual rate. Sometimes a new traffic signal will help to reduce the actual rate, although it is not uncommon for rear-end accidents to increase once a signal is installed.
