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Construction approach cuts work zone congestion and crashes

Full road closure is an approach designed to eliminate the exposure of motorists to work zones and workers to traffic by temporarily closing a road for rehabilitation or maintenance.

Full road closure is an approach designed to eliminate the exposure of motorists to work zones and workers to traffic by temporarily closing a road for rehabilitation or maintenance. Traffic is detoured during full road closure, allowing construction crews full access to roadways or bridges. A full-closure strategy can be an effective way to reduce traffic congestion caused by construction, finish projects faster, improve quality, and enhance safety for motorists and highway workers.

Design-build (D–B) is a method of project delivery in which the design and construction phases of a project are combined into one contract and awarded on either a low–bid or best–value basis. D–B projects allow for greater private sector participation in the delivery of transportation projects. Agencies can focus on policy and planning, leaving the private sector to deal with cost efficiency and construction risk, which it is in the best position to manage. Medium–to–large transportation projects are best suited to D–B project delivery because the agencies involved with larger projects typically have sufficiently knowledgeable staff to prepare the comprehensive contract documents required to clearly delineate roles, responsibility, and liability.

Work zones are a necessary part of maintaining and upgrading the nation's aging highway system, but they account for nearly 24 percent of nonrecurring congestion, or 482 million vehicle hours of delay each year. From 1982 to 2002, route miles of highway increased 3 percent while vehicle miles of travel jumped 79 percent. The combination of more work zones and heavier traffic means construction congestion is having a greater impact on roadways.

Despite the growing need for work zones, construction congestion frustrates motorists. In a Federal Highway Administration survey, Americans cited work zones as second only to poor traffic flow in causing dissatisfaction with the roadway system. More than 60 percent of those surveyed were dissatisfied with the speed of repair and traffic congestion related to work zones. Safety is also an important work zone issue that affects both travelers and construction workers. In 2006, 1,010 fatalities occurred in work zones. More than 40,000 people are injured each year in work zone crashes.

Full road closure is one method highway agencies are using to balance the need for work zones with concerns about mobility and safety. The full–closure approach can be used for an extended time period, on weekends or nights, or in one direction at a time to reduce the impact of work zones and speed construction. In situations with adequate alternate travel routes, a good traffic management plan, and effective public outreach, full closure can be a viable alternative to typical construction approaches. In traditional part–width construction, at least one lane of traffic in each direction is kept open while work is underway on other lanes.

An FHWA study concluded that full road closures can be a successful tool for reducing the impact of work zones. On the six projects studied, construction time was reduced by an average of 76 percent compared with traditional part–width construction.

An FHWA study concluded that full road closures can be a successful tool for reducing the impact of work zones. On the six projects studied, construction time was reduced by an average of 76 percent compared with traditional part–width construction.

The study cited several benefits of full road closures:

• Expedite project completion and, in some cases, reduce construction costs
• Reduce the impact of construction on travelers
• Improve safety for workers and travelers.
• Reduce work zone–related crashes and fatalities
• Maximize the workspace available to the construction contractor and increase productivity
• Result in a smoother, higher quality roadway because of full–width construction

Many highway agencies have used full road closures successfully:

• The Minnesota Department of Transportation used a 5–month closure to cut 60 percent from the timeline to reconstruct a section of Highway 36 in North St. Paul. The closure also cut project costs by 15 percent and resulted in a better quality highway.
• The Delaware Department of Transportation rehabilitated a 6–mile stretch of Interstate 95 in Wilmington by shutting down the road in one direction at a time, reducing construction time from 2 years to 185 days.
• The Missouri Department of Transportation used a full–road closure when it replaced the Chouteau Bridge in St. Louis. The 2–year project, which included a strategy to maintain access to area businesses, was completed ahead of schedule.
• The Oregon Department of Transportation opted for full closure in one direction at a time when it repaved the Banfield Freeway in Portland, the busiest road in the state. The agency completed the project in two weekends instead of the 32 nights it would have taken using traditional part–width construction.
• The Michigan Department of Transportation used full closure to speed construction and improve safety when it rehabilitated part of the Lodge Freeway in Detroit. The closure saved at least 75 percent on traffic maintenance costs during construction.

For More Information

• FHWA Web site on full road closure strategies and case studies, www.ops.fhwa.dot.gov/wz/construction/full_rd_closures.htm
• Full Road Closure for Work Zone Operations: A Cross-Cutting Study, http://ops.fhwa.dot.gov/wz/resources/publications/FullClosure/CrossCutting/its.htm
• FHWA Web site on work zone mobility and safety, www.ops.fhwa.dot.gov/wz/index.asp
• Moving Ahead: The American Public Speaks on Roadways and Transportation in Communities, www.fhwa.dot.gov/reports/movingahead.htm

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