Rea Contracting LLC and HDR Inc. have been using a phased approach to construct 8.1 mi. (13 km) of I-77 in Charlotte, NC. The project is on track to be successfully complete in June 2004 — 125 days ahead of the original completion date.
This $83-million project, which began in 2001, involved eight laning I-77 from its interchange with I-85 north to the proposed Charlotte Outer Loop (I-485). One lane going in each direction will be designated a high occupancy vehicle (HOV) lane.
According to Tawana Brooks, North Carolina Department of Transportation (NCDOT) construction engineer, the widening was necessary to increase the traffic-carrying capacity, reduce delays and improve mobility and safety to the traveling public.
“It was also determined necessary to add the HOV lanes,” Brooks said, “due to heavy traffic growth in the metropolitan Charlotte area, with average daily traffic and peak-hour flow of 90,000 to 140,000 vehicles.
“The new project corridor will provide access to Charlotte’s employment centers for a substantial number of commuters who live in the northern areas of Mecklenburg County, including the towns of Huntersville, Cornelius, Davidson and the Lake Norman community. The new construction will increase the traffic-carrying capacity, improve the flow of traffic, and reduce the accident potential,” she said.
NCDOT elected to use a design-build delivery method, said Bill Moyers, Rea Contracting project manager, so the project would move from the planning stage to the construction stage faster than a traditional design-bid-build method, ultimately reducing traffic disruptions and costs.
Brooks noted the project was funded by state earmarked funds for design/build construction.
To allow the design effort to flow at a more uniform pace and to lessen the impact of potential design and construction delays, Rea Contracting implemented a phased approach to both the design and construction portions of the project.
The widening was divided into four smaller projects with the designs being completed just days ahead of planned construction.
These smaller design packages, referred to as “releases for construction,” or RFCs, allow for phases of construction to begin without a full set of plans. The final set of plans is developed while construction progresses toward the completion date.
To ensure the quick construction package review time necessary to keep the aggressive schedule required by NCDOT, all reviews of construction packages were to be done in 10 days, as opposed to 45 days for traditional construction. The benefit of using this method is that the project has been completed in three years rather than the five to six years it might have taken on a more traditional work schedule.
“While the design-build method is gaining acceptance,” Moyers said, “it is still new to North Carolina highway construction and as a result, we all had to learn and grow together.”
According to Moyers there were many challenges faced on this project because of the heavy traffic volumes and the reduced time frame for completion of the project.
Despite this, the project won several national awards for innovations used to deal with these challenges, Moyers said.
“The most notable were the awards presented to the design team from the American Road and Transportation Builders Association [ARTBA] and the National Asphalt Paving Association [NAPA]. Both awards were received for the installation of a temporary ramp from Harris Boulevard to the median of I-77. This allowed construction traffic — especially asphalt trucks — to access the median work without impacting the I-77 traffic.
“Our goal was to have a project that was constructable, while not sacrificing the safety of the traveling public, our subcontractor’s employees and our own employees. This required a total team effort,” Moyers said.
Rea Contracting has offices in Charlotte and Raleigh, NC; and Columbia and Beaufort, SC. Rea led the design-build team, managed the construction of the project, performed the structure and bridge work, placed the asphalt pavement, performed the milling, installed and maintained the traffic control, and will place the concrete pavement on the I-77 southbound ramp to Harris Boulevard.
Moyers said three Superpave asphalt mixes were used: B-25 c, I-19 d, and S-12.5 d. Also, approximately 425,000 tons (385,553 t) of asphalt were laid.
A Cedarapids 561 was used for paving, an Ingersoll-Rand DD-110 was used for compacting and a 1997 Roadtec RX45 was used for milling. All equipment was serviced and owned by Rea.
HDR Inc. provided the design work for the I-77 project. Wayne Moody was the lead designer.
F.T. Williams Inc. was hired as the grading subcontractor.
A future Charlotte project currently in the planning phases will widen the section of I-77 from I-485 to NC-73 (Sam Furr Road) to a six-lane freeway.