Evaluation of Work Zone Traffic Control Enhancements

In an attempt to improve work zone safety, the Iowa Department of Transportation (DOT) initiated a research project to determine the overall effectiveness, including functionality, of several proposed work zone traffic control devices. These devices included: portable rumble strips, flashing STOP/SLOW paddles, BE PREPARED TO STOP signs with fluorescent orange sheeting, orange flags, amber strobe lights, fluorescent yellow-green flagger vests, and additional flagger. The research project began in June of 1995 and ended in July of 1996. The research was conducted in two phases with the first phase using asphalt paving operations and the second phase using Iowa DOT maintenance operations. Motorist survey cards and Iowa DOT employee questionnaires were the primary measures of effectiveness in phases 1 and 2 respectively.