Authors: Mark Franz and Gang-Len Chang
Conference: 90th TRB Annual Meeting in 2011
Abstract:
The Maryland State Highway Administration has started a pilot program to evaluate the effectiveness of an automated speed enforcement system in work zones. Three sites were selected to measure the spatial and temporal effect of automated speed enforcement on motorists’ speeding behavior. In addition to comparing the temporal changes and spatial evolution of mean and 85 percentile speeds, the spatial and temporal change in percentages of three motorist populations, conservative, normal and aggressive drivers, were considered. A total of five datasets were analyzed. For the two data sets that compared the before versus during analysis periods, the enforcement period displayed a general reduction in aggressive motorists while creating a more stable spatial speeding distribution through the work zone. Two of the three data sets comparing the during versus after enforcement periods showed that motorists may learn where enforcement is taking place and adjust their speeds accordingly. This effect was evident even after the enforcement period. Lastly, one dataset displayed increased speeds and less stable spatial speeding patters during the enforcement period, suggesting the need for further investigation of this data set.