North Carolina's Knightdale Bypass

14-mi. bypass to relieve congestion along U.S. Highway 64 into Raleigh

by Carter Langston

An aggressively scheduled 30-month highway construction project is taking shape around Raleigh, N.C., although it's running a little late.

Due to unusually wet weather, the $170 million Knightdale Bypass is expected to be substantially complete by spring, rather than the earlier Dec. 31 target. There are two major contracts - North Carolina Constructors' $131 million design-build contract, and a $40 million effort being overseen by Vecellio & Grogan.

"The weather was the most critical variable through the end of the year," said Steve Leonard, resident engineer with the North Carolina Department of Transportation in Raleigh.

The congested U.S. Highway 64 is the main corridor connecting Raleigh to the eastern part of North Carolina. Once complete, the Knightdale Bypass will connect U.S. 64 East with Interstate 440.

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Since work on the 14-mi., six-lane bypass started in July 2002, there have been ice storms, eight hurricanes, unusually heavy rain, cement shortages and bridge building hurdles in regulated wetlands. All caused delays.

In November 2002, a severe ice storm froze the region and delayed work for days. Weather has been a constant test since. Temporary erosion control devices and access roads were frequently washed out, destroyed or clogged. And the region's red clay soil holds water for days after heavy rains.

"We lost six weeks to eight named storms," said Paul Newman, project manager with North Carolina Constructors. "We need unusually and unseasonably dry weather to achieve our substantial completion target."

Substantial completion means that traffic may course the new artery, but construction may not be fully complete until June.

NCC, a 60/40 joint venture between HBG Flatiron and Lane, is responsible for 9.6 mi. with a $131 million design-build contract. The company responded to delays by increasing work schedules from six to seven days on priority operations.

"NCC capitalizes on the strengths of the two companies," Newman said. "Flatiron took the lead in bridge building and Lane leads the concrete paving."

Longmont, Colo.-based Flatiron erected 23 bridges at 15 sites, including six precast bridges that feature a drilled shaft into riverbeds below. Construction in the highly regulated wetlands required temporary work structures to position cranes and other equipment without harm to the banks below.

Newman said the bridges are 99 percent complete. Remaining work includes finishing the expansion joints and paving the approach.

The most demanding bridge sites were Bridge 2 and Bridge 4. The length of Bridge 4, which spans 1,500 ft. over Mango Creek and the Neus River, made it the most difficult. Newman said that Bridge 2, which actually comprises two structures, was complicated because both structures were erected almost simultaneously over Crabtree Creek.

At the Bridge 2 site, there's the mainline bridge on the bypass and a crosscutting overpass.

"We drilled the shafts for the overpass at the same time that we drilled the shafts for the mainline bridge," Newman added. "The different elevations made this the second most complicated bridge construction."

Joint venture partner Lane, headquartered in Meriden, Conn., was hampered by a cement shortage during 2004 and has been about a month behind schedule. The mainline is comprised of 290-mm-thick concrete pavement resting on a 75 mm permeable asphalt drainage layer on a 25 mm asphalt surface. Those layers top a 200-mm-thick lime- or cement-treated subbase.

Mangum Construction is completing the asphalt work along the shoulders.

The final mile that ties the new bypass with existing traffic along U.S. 64 East has been prepared, but not paved. That's the last phase and work is expected to conclude in time for the spring substantial completion date.

NCC employed 15 subcontractors. The largest was Glover Construction of Pleasant Hill, N.C., which excavated about 2.85 million cu. meters of dirt and rock.

Knightdale Bypass is the first project for NCC.

"We make a good team," Newman said of the joint venture. "NCC is currently bidding on another highway construction project near Lexington."

Recent legislation allows NCDOT to let up to 25 design-build projects each year. In 2005, the department expects to issue about seven or eight design-build contracts.

The Knightdale job is Leanard's first experience with design-build, and he said it has been "a good personal experience for me. [NCC] is a good design-build contractor, organized and good at coordinating work."

While NCC won the fast-tracked mainline contract, Vecillio & Grogan took the $40 million interchange and flyover section, connecting the final 2 mi. of the mainline to I-440 and New Hope Road.

This section, also expected to be substantially complete within the first quarter of this year, consists of concrete and structural steel.

As work along the mainline winds down, another contractor, Barnhill Construction, is working in tandem on a tie-in ramp for a future project connecting the bypass with Highway 540. The coordinated effort will ensure that traffic along the Knightdale Bypass is not impeded as work continues on the Highway 540 outer loop through 2006.