SPEED CONTROL MEASURES IN RESIDENTIAL AREAS

The effectiveness of some regulatory and channelization measures to achieve speed reductions was evaluated using the 95th percentile speed as the parameter for comparison, STOP signs were found to be the most effective device to reduce speeds, with the top speeds recorded being 10 mph. Traffic circles are the next most effective with top speeds ranging from 16 to 22 mph, more than twice the speeds at STOP sign locations. Rumble stips are the third most effective with top speeds ranging at different locations from 17 to 35 mph. Street narrowings were almost totally ineffective. The area of influence of a STOP sign in terms of speed reduction was about 100 to 200 feet on either side of the device. Approaching a traffic circle, motorists start deceleration later. The speeds of motorists leaving a traffic circle do not equal those of motorists leaving a STOP sign until they are about 150 feet past the intersection.