According to the U.S. Department of Transportation's Federal Highway Administration (FHWA), run-off-road crashes account for nearly one-third of deaths and serious injuries annually.
Inattentive driving has been linked to these types of crashes (FHWA, 2001). As a remedial measure, rumble strips have been installed on roadways to alert inattentive drivers that deviate from the travel way. This research attempted to measure the safety benefits achieved from rumble strips along roadways in Connecticut. Safety benefits are considered a reduction in single-vehicle, fixed object, run-off-the-road accidents. From the results of the data description, the number of "rumble strip related" (single vehicle, fixed object, run-off-the road) accidents decreased as well as the number of "asleep" and injury/fatal accidents.
The study incorporated a methodology that uses comparative sections to predict the "what if" scenario of the number of accidents that would have occurred if rumble strips had not been installed. The statistical analysis calculated an index of effectiveness based on accident data for the rumble strip and comparison sections. The index of effectiveness showed a decrease in "rumble strip related" accidents for the collected accident data. This study used the Comparison Group methodology to predict rumble strip accidents, without reference to causal factors such as driver behavior, accident reporting, and traffic counts.