ITS Technologies in Work Zones

With the National Highway System essentially complete, and many roads surpassing their useful design life, the focus of roadwork has shifted from new construction to rehabilitating and improving existing facilities. The share of capital funds used for system preservation rose from 47.6 percent in 1997 to 52.0 percent in 2000. As a result of this trend, transportation agencies must perform a greater number of projects on roads carrying traffic. As vehicle travel continues to increase significantly faster than roadway miles, work zones exacerbate the growing congestion problem. Between 1980 and 2000, roadway lane miles increased 3.8 percent, while vehicle miles of travel grew 80 percent. From 1982 to 1999, “rush hour” increased from 2-3 hours to 5-6 hours. ITS technologies increasingly are being used to anticipate and mitigate congestion caused by highway work zones. These technologies provide ways to better monitor and manage traffic flow through work zones and increase safety for both workers and road users. By easing congestion and improving traffic flow, ITS technologies can reduce construction time and costs. ITS technologies also improve incident detection, response, and clearance in work zones; this is particularly important because traffic capacity often is reduced in work zones, and incidents in these areas cause even greater congestion and increase the potential for secondary crashes.