North Carolina DOT Closes the Greensboro Urban Loop
The Greensboro Urban Loop is part of the North Carolina Department of Transportation's plan to improve traffic flow within and around the city. Construction of the loop will allow traffic to bypass Greensboro and improve congestion on existing I-40, particularly in the loop that includes I-40, I-85 Business and U.S. Routes 29, 70, 220 and 421.
There are four projects in various stages of construction that which will complete the remaining 15 miles of the 44-mile long loop around the city. The first to break ground is known as Western Loop (STIP number U-2524C), in northwest Greensboro. Construction began in October 2013 and is expected to be complete in March 2018. (See sidebar for description of other projects.)
"This section will tie into I-840 that runs from I-40 to Bryan Boulevard by extending the Loop to a major corridor, the primary route of U.S. 220," saidDivision Seven Construction Engineer Patty Eason. "Traffic volumes along U.S. 220 are significant and include a large number of trucks coming from Rockingham County and Virginia. This section will provide access to interstate routes I-40, I-85 and existing I-73 for east, west, north and south commercial and vehicular traffic."
Eason explained that traffic volumes, congestion, travel time and destinations along with public and local government input were the major considerations in the decision as to which section was phased prior to another.
Scheduling Around Funds
Funding availability was also a consideration in amount of work that could be scheduled. The $123 million project is being funded with Federal and State funds. The project was advertised for eight weeks and awarded to the lowest, qualified bidder. Vecellio & Grogan Construction won the contract.
The freeway project is 4.4 miles long, six lanes total, with three in each direction. In addition to the roadway, tasks on the project include:
Completing the Greensboro Loop/Bryan Boulevard Extension interchange (to provide northern Greensboro with a more direct route to Piedmont Triad International Airport)
Constructing a bridge on Fleming Road and Horsepen Creek Road over the Greensboro Loop
Constructing a cul-de-sac at the end of Oneida Road north of the Greensboro Loop
Constructing bridges on the Greensboro Loop over Drawbridge Parkway and Horsepen Creek tributary and wetlands
Constructing an interchange at the intersection of the Greensboro Loop and U.S. 220 (Battleground Avenue)
Division Seven Engineer Mike Mills said one of the notable challenges of the project so far was the bridge over wetlands. With a span of over 4,000 feet and mandate to protect the wetlands, the contractor had to build extensive temporary work platforms.
"The temporary work platforms were used to construct the bridge over the wetlands," Mills said. "This allowed the cranes and drill rigs to work in the wetlands with minimal to no damage."
"The contractor has been very conscientious of environmental requirements and responsive to any issues that have occurred," said Mills.
Mills also credits the contractor with a material and time saving change to the design of the project. Vecellio & Grogan looked at one of the bridges that crossed and angled road and suggesting squaring up the piers rather than following the angle.
"The original design for the bridge in this area was on a skew and would require the steel girders to be designed for that skew," Mills said. By eliminating the skew, the cost for the girders was significantly reduced, as was the manufacturing time.
"Placement of the girders without being skewed can also be done more expeditiously due to ease of handling," he said.
Another efficiency factor on the project is in the use of technology. GPS on grading and paving equipment allowed project to be stakeless, Mills said.
The Loop by the Numbers
Eason said unclassified excavation was approximately 1.2 million cubic yards, with the borrow quantity only approximately 67,000 cubic yards. Concrete paving on travel lanes was approximately 130,000 square yards; asphalt quantity is approximately 52,000 tons of base course; 36,000 tons of intermediate course; and 31,000 tons of surface course. Unclassified earth material was all used within project if at all possible, minimal wasted; any milled asphalt was reused at asphalt plant.
Structural steel was estimated at over 13 million pounds and 36,000 linear feet of concrete girders.
Crew size varies greatly depending on the operations being performed and the number of subcontractors on the job, Eason said. As of September, 156,500 man-hours have been performed. The project is approximately 65 percent complete.