The pavement will be removed over the entire 7-mile-long project. Built in the early 1950’s, the aged concrete has exceeded its life expectancy.
“We’ve been maintaining it for many years knowing it should be rebuilt,” says Brad Swanson who is an MDOT-Gaylord TSC Construction Engineer and is overseeing the contract for the U.S. 31 rebuilding project. “It’s been a rough riding pavement, particularly in the winter months, and the condition can cause damage to vehicles.”
To keep the road operable, MDOT has had to do a good deal of ongoing maintenance including putting asphalt down over the top layer, replacing joints, and minor resurfacing. A few years ago, they added asphalt shoulders and widened a section of U.S. 31.
The highly-used route – which has an average traffic count of 8,500 vehicles per day – sees wide fluctuations in traffic depending upon the time of year, as traffic can be triple or even quadruple in the summer months. During the busy season, the road is congested.
The scope of the project includes removing and replacing the pavement all the way down to the subgrade. Miscellaneous safety and drainage improvements – including installing new concrete curb and gutter, as well as installing a water main replacement – are also part of the project. The team is building deeper and wider ditches for surface water run-off. High and dry, the area has lots of sandy soil.
Currently, the route has two 12-foot lanes in the area. Over a 2.5-mile stretch, the route will be widened to include a center left turning lane. New guardrail and pavement markings will also be installed as part of the project.
“We need to maintain commuter access, and to continue to provide access to local business and residents,” Swanson says. That’s led to a lengthy detour that adds 10 minutes to a commute. “There are few options in the area in terms of roads and access that are conducive to highway traffic.”
When working on old roads, there’s always the potential of unknowns as plans are not always up to date. The team has come across utilities that were not marked, which has caused some delays.
For this project, MDOT is using intelligent compaction, which is the compaction of road materials using modern vibratory rollers equipped with an integrated measurement system, an onboard computer reporting system, GPS-based mapping, and optional feedback control. Intelligent compaction rollers facilitate real-time compaction monitoring and timely adjustments to the compaction process by integrating measurement, documentation, and control systems. Intelligent compaction rollers also maintain a continuous record of color-coded plots, allowing the user to view plots of the precise location of the roller, the number of roller passes, and material stiffness measurements.
Because MDOT is fairly new to this technology, there’s been a learning curve. However, Swanson is optimistic about the benefits that intelligent compaction provides. “It speeds up construction, leads to less guesswork about what’s been covered, less fuel consumption, and less manhours,” Swanson says.
While MDOT analyzed production rates and found that one season is well within the contractor capabilities, it still requires an aggressive schedule. Therefore, construction is taking place six or seven days per week, and the crews are working long hours.
Swanson notes that the project has three milestone completion dates. The project is behind schedule on the first milestone due to the extra utility work that arose. “However, we found efficiencies and anticipate more and expect that we will finish on schedule or even a bit ahead of schedule,” Swanson says. Among the efficiencies Swanson is referring to is intelligent compaction. He expects its impact to be greater as the project moves forward since the crew is growing more comfortable and adept at using the technology.
In addition, Swanson is confident in the contractor. The general contractor is a joint venture between J&N Construction and DJ McQuestion and Sons. “We have lots of familiarity and comfort with them and have developed a great partnership with them over the years,” Swanson says.
Despite some modifications which have made a negligible change, the project is on budget. “Our team put together a high-quality survey and design which allowed the contractor to make an accurate and reasonable bid,” Swanson says.
When the U.S. 31 Rebuilding project is complete, commuters, tourists, and local and commercial traffic will have an improved surface to travel on. It will support commerce and travel for years to come. The project will also allow MDOT to focus money and services elsewhere since U.S. 31 will no longer require extra maintenance.