Left: Boulder's ambitious Broadway Street and Bridge Reconstruction Project—which included building a storm sewer under existing utilities—only minimally disrupted traffic. Above: The Boulder Creek Path pedestrian thoroughfare runs under the newly constructed Broadway Bridge. Photos: Boulder, Colo., Public Works Department
Today more than ever, you have to justify the cost of road construction delays. For complex, high-profile projects, many agencies offer contractors financial incentives for early completion—and impose penalties for lateness.
One factor affecting the schedule is the staging of traffic around work zones. To speed up completion, most agencies allow contractors to propose changes to traffic management designs.
“If a contractor comes to us to propose a design change that can save time and money, we'll consider it as long as it doesn't adversely affect safety,” says Eric Harm, deputy director for the Division of Highways at the Illinois DOT (IDOT).
One example of effective traffic management comes from a high-profile project running through the heart of Boulder, Colo. The $8.9 million Broadway Street and Bridge Reconstruction Project involved total reconstruction of a four-lane arterial that carries 30,000 vehicles per day.
The project had nine busy intersections, seven of them signalized. Pedestrian and bicycle activity within the Broadway corridor is significant. According to Alex May, transportation project manager for the city's Department of Public Works, 15,000 pedestrians cross Broadway at the Pearl Street Mall every day, and approximately 5000 pedestrians and bicyclists use the Boulder Creek Path, which crosses under the Broadway Bridge. Broadway also is multimodal, serving both regional and local buses.
The 15-month project reconstructed ¾ mile of roadway and streetscapes, replaced the historic Broadway Bridge over Boulder Creek, enhanced pedestrian and bicycle facilities, and renewed major utilities. Funding came from the city of Boulder, the Colorado DOT, and the Federal Highway Administration (FHWA); financing came from the Denver Regional Council of Governments'Transportation Improvement Program.BEATING THE CLOCK
Successful traffic management was central to the project, says Dick Brasher, project manager for the city's contractor, Concrete Works of Colorado.
“We worked with the city to tackle several intersections more aggressively than on the original plans,” he says. “The city set up the project with an early completion incentive/disincentive of more than $500,000, so that gave us the incentive to work long hours. We earned the full incentive and trimmed several months of construction time.”
Utility, roadway, and bridge tasks were completed in November 2003. Final streetscape and landscape improvements wrapped up in spring 2004.
To help beat the deadline, Concrete Works of Colorado used high-early-strength concrete—which strengthens quickly after being poured—in most, if not all, of the six major intersections. This type of concrete was required to attain a 3000-psi opening strength within 24 hours of placement, according to May. The project included 23,000 square yards of concrete pavement placed 9½ inches thick, with 7900 square yards of high-early-strength concrete. Intersections were paved with concrete by hand with a vibrating screed during evenings and weekends, and were built in quarters to allow traffic to flow in all directions during construction.
— Brown is a freelance writer in Des Plaines, Ill.