Colored Entrance Treatments for Rural Traffic Calming

A number of traffic-calming devices were evaluated to determine their effectiveness in reducing speeds along the main road through a small rural community. Five different treatments were selected and installed in six rural Iowa communities. This tech brief highlights use of colored entrance treatments. Pneumatic road tubes were used to collect speed and volume data before and after installation of the rural traffic-calming treatments. Data were typically collected for 48 hours on a Monday through Friday under mostly dry weather conditions. Speeds decreased at all three sites with decreases up to 2.3 mph in mean speeds. All sites had decreases in 85th percentile speeds of 2 mph. The fraction of vehicles traveling 5 or more mph over the posted speed limit decreased by 30 to 44 percent and the fraction of vehicles traveling 10 or more mph over the posted speed limit decreased by about 40 percent for all sites. A large decrease resulted in the fraction of vehicles traveling 15 or more mph over the posted speed limit (up to 100 percent). No change was noted in the fraction of vehicles traveling 20 or more mph over the speed limit.