A portable travel time prediction system was deployed in a work zone on a congested, 13-mile segment of I-75 northbound near Dayton, Ohio. The system included five microwave vehicle detectors, four Dynamic Message Signs (DMS), solar power systems, microprocessors, a computer, and a radio communication system for data transfer between the microprocessors and the computer and between the computer and the DMS. The microprocessors calculated traffic volume and occupancy for each lane. The system computer collected traffic flow data from the microprocessors, computed estimated travel times, and displayed travel time and distance to the end of the work zone on three DMS positioned in advance of exit ramps. The fourth DMS was placed at the beginning of the work zone and displayed "WORKZONE ENDS 14 MILES."

To assess the perceptions of the motoring public, data were collected during a three-day period in October 2000. Three crews of Ohio DOT personnel drove through the work zone for 12 hours each day. The crews recorded Ohio license plate numbers of private vehicles. The field data were used with an Ohio Department of Public Safety database to generate a list of names and addresses of registered owners. A seven-question survey was distributed to 3,177 vehicle owners. Anonymous survey responses were collected by the Ohio DOT and forwarded to researchers at Ohio University. Eight hundred and nine (809) survey questionnaires were returned and 660 were analyzed. Thus, the return rate was 21 percent.

Analysis of survey results revealed that 60 percent of respondents utilized the predicted travel time information to exit I-75 earlier than planned; for frequent users this percentage climbs to nearly 72 percent. Approximately 28 percent of respondents indicated that the predicted travel times were accurate and reliable, while 42 percent felt the travel times were sometimes accurate and reliable, and sometimes not. Roughly 90 percent of respondents thought that the predicted travel times were sometimes or always useful. Nearly 97 percent of respondents felt that a travel time prediction system for work zones would be helpful or may be helpful to the motoring public.

Researchers concluded that the real-time travel time prediction system was a definite improvement over static non-real-time display systems. It generally provided useful and relatively accurate travel time predictions to the motoring public and appeared to be perceived by almost 97 percent of drivers as helpful and useful.