Work zones seem to be everywhere. And, they always seem to mean traffic delays. The perception is not far from the reality. For example, an estimated 3,110 work zones were present on the National Highway System during the peak summer roadwork season of 2001. This meant that motorists encountered an active work zone one out of every 100 miles and a lane closure every 200 miles. It is not surprising that work zones on freeway account for nearly 24 percent of non-recurring delay. In addition, work zone safety is a major concern in the United States, with 1,065 fatalities and more than 40,000 injuries resulting from work zone crashes in 2004 alone.
An image of a work zone with back up traffic.
Travel time reliability is also a key factor associated with work zones, with travelers reporting being frustrated with the delays and unexpected road conditions caused by work zones. This is particularly an issue for road users when a project is in progress but no work appears to be going on for days at a time, yet congestion and delays continue to occur.
Traffic volumes and congestion are increasing, but little corresponding growth in road miles is happening. Many of the Nation's highways are approaching middle age, requiring additional construction and repair, and thus more work zones. Increasingly, construction is taking place while traffic continues to flow on the facility undergoing repair, which applies great pressure on contractors to compress schedules, finish projects early, and perform work art night while maintaining safety and quality.
These trends pointed to a strong need for updating the Federal regulations governing safety and mobility in work zones. The USDOT responded by publishing a new Work Zone Safety and Mobility Rule in September 2004. The updated Rule provides a decision-making framework for considering the broader safety and mobility impacts of work zones across all stages of a project. It also facilitates the implementation of appropriate strategies to help manage those impacts. Compliance with the updated rule is required by October 12, 2007.