Knowledge Resources

In this study, the QuickZone traffic analysis tool was used to compare traffic conditions with and without the provision of real-time work zone traffic information at a representative two-mile work zone on I-95 in North Carolina. The system evaluated was designed to monitor traffic conditions in real-time, determine expected traffic delays, and advise motorists of current delays and alternate route information using portable dynamic message signs (DMS) and an Internet Web site. The goal was to reduce demand in the work zone during periods of heavy congestion.

The rehabilitation project covered a 19-mile section of I-95 and included multiple work areas. The design and size of each active work area was dependent on the location of detour routes, and need for lane closures and traffic controls. The segment of the work zone selected for analysis in this study was located between Milepost 150 and Milepost 154, and was about two miles long.

Baseline conditions were modeled using traffic information provided by the North Carolina DOT and traffic pattern data derived from the Highway Capacity Manual. To compare traffic conditions with and without ITS, two identical construction phases were simulated for one week each, with the only difference being the presence of ITS.

The results of the analysis indicated that when real-time work zone traffic information was provided; the maximum queue length decreased from 2.94 miles to 1.3 miles, maximum traveler delay decreased from 14.8 minutes to 6.6 minutes, and total user delay decreased from 21,955 hours per week to 5,476 hours per week—a reduction of 16,480 hours.

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