In North Carolina, a survey of local residents near the Smart Work Zone systems found that over 95 percent of motorists surveyed would support use of these systems in the future.
Date Posted
04/29/2008
Identifier
2008-B00533
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Effect of Intelligent Transportation Systems in Work Zones: Evaluation of North Carolina Smart Work Zones - Final Report

Summary Information

This study evaluated the deployment of two Smart Work Zone systems that supported roadway resurfacing activities on Interstate 95 between April and November 2003. One of the projects took place in Nash and Halifax counties between milepost 145 and 154 near the community of Rocky Mount, and the other project was located in Johnston County between milepost 101 and 107 near the community of Smithfield. The information presented in a Smart Work Zone is based on the most current conditions which are constantly being monitored by the system throughout the duration of the construction project, providing reliable, accurate, and timely information to the motorists.

System implementation included three portable sensor trailers with cameras positioned upstream of the work area to monitor traffic conditions. The sensors collected occupancy data and the cameras provided video images of traffic conditions. Based on traffic condition data that was collected and observed, information was displayed to travelers on three portable message signs upstream of the work area with one of those signs positioned prior to the alternate route. An additional three portable message signs were then positioned along the alternate route to provide route guidance. Three levels of messages were displayed based on the traffic conditions. As an example, when no delays were detected the message might read "Real Time Traffic Info / No Delay Exits 150-141". When there were short delays, but an alternate route warning was not warranted, a typical message might read "Traffic Stopped Ahead / 15 Minute Delay". When the delay reached the point where the alternate route would provide a shorter travel time, a typical message might read "Traffic Stopped Ahead / 20 Minute Delay / Use Exit 141 As Alt.".

Although it was not feasible for the system to be turned off for evaluation purposes, there were short periods of time available when the system was not operating (due to work zone relocation activities) that enabled researchers to conduct "with" and "without" analysis. Other methods for collecting data to evaluate the system included mail-out and road-side surveys, using a portable camera system deployed as part of the work zone system, and hand-held video cameras. The data was logged by the system and examined to determine levels of congestion experienced during system deployment.

RESULTS

Survey data collected from 333 motorists that reside near the work zone systems evaluated indicated that 80 percent of the motorist respondents were aware that the system was providing up to date information compared to other work zones, and they perceived the information as "always accurate" or "sometimes accurate" in over 95 percent of cases. Approximately 95 percent of respondents supported the future use of these types of systems in North Carolina. In addition, survey data collected from seven trucking companies with operations in the area showed 100 percent support for future deployment of Smart Work Zone systems.