In North Carolina, Smart Work Zone systems increased alternate route usage by 10 to 15 percent when specific delay and alternate route information was posted on roadside dynamic message signs.

September 2004
Rocky Mount,North Carolina,United States; Smithfield,North Carolina,United States

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.


Using the portable and hand-held cameras at the work zone, traffic volumes were counted during periods of time when different sign messages were displayed. The evaluation of this data determined that the Smart Work Zone system increased alternate route usage by 10 to 15 percent when specific delay and alternate route information was posted on roadside dynamic message signs.

Benefit Comments

No comments posted to date

Comment on this Benefit

To comment on this summary, fill in the information below and click on submit. An asterisk (*) indicates a required field. Your name and email address, if provided, will not be posted, but are to contact you, if needed to clarify your comments.


Effect of Intelligent Transportation Systems in Work Zones: Evaluation of North Carolina Smart Work Zones - Final Report

Author: Bushman, Rob and Curtis Berthelot

Published By: North Carolina DOT

Prepared by the University of Saskatchewan for the North Carolina DOT

Source Date: September 2004



Average User Rating

0 ( ratings)

Rate this Benefit

(click stars to rate)


Benefit of the Month for January, 2009 !

Goal Areas


Typical Deployment Locations

Rural Areas


Dynamic Message Signs, CMS, VMS, Changeable Message Signs, Variable Message Signs, construction warning signs, Portable Dynamic Message Signs, portable CMS, portable VMS, portable Changeable Message Signs, portable Variable Message Signs, Temporary Dynamic Message Signs, Temporary CMS, Temporary VMS, Temporary Changeable Message Signs, Temporary Variable Message Signs, smart work zone systems, smart work zone, smart work zones, Smart work zones, workzone, WZ

Benefit ID: 2008-00532