A half-century after designing the Midtown Tunnel between Norfolk and Portsmouth, Virginia, Parsons Brinckerhoff designed the Second Midtown Tunnel, which when completed will double traffic capacity across the Elizabeth River.
Since the first Midtown Tunnel was built in 1962, it has operated as a two-lane, bidirectional thruway along US Route 58. When it opened, it accommodated 8,400 vehicles a day. Today that volume has increased to 38,000 vehicles.
“This is the most heavily travelled two-lane road segment east of the Mississippi River,” says Derek Piper, Deputy Design Manager for Parsons Brinckerhoff. “It greatly exceeds capacity, and because there are not many options to re-route traffic, everything shuts down if there is a breakdown
Parsons Brinckerhoff played a role in the design of all four Elizabeth River tunnels, including the first Downtown Tunnel, which opened in 1952; and the second Downtown Tunnel, completed in 1982. Parsons Brinckerhoff also designed the Hampton Roads bridge-tunnel crossings, completed in 1957
The new two-lane Second Midtown Tunnel, together with other traffic improvements in the area, will cut travel time by an average of 30 minutes per trip during peak commuting hours, Piper says. The project recently passed the halfway point and is slated for
Parsons Brinckerhoff is lead designer for SKW Constructors, a joint venture of Skanska USA Civil Southeast, Kiewit Construction Company, and Weeks Marine. SKW is the design-build team for the owner, Elizabeth River Crossings, a corporation created to execute the project under a public-private partnership (P3) with the Virginia Department
The $2.1 billion project also includes rehabilitation of the existing Midtown Tunnel, improvements to the two existing Downtown Tunnels, and a 1.6 kilometer (1 mile) extension of the Martin Luther King Jr. Freeway—an elevated four-lane, north-south expressway with a raised median that will provide an enhanced link between the Midtown and Downtown tunnels
Parsons Brinckerhoff is currently providing construction-phase services, which includes plan revisions, responses to requests for information, shop drawing review, preparation of
The Elizabeth River Tunnels Project is the largest design-build project in the history of the Hampton Roads region. The Second Midtown Tunnel is the first deep-water concrete immersed tube in North America, and the second all-concrete immersed tunnel
Parsons Brinckerhoff recommended the all-concrete option for the two-lane tunnel over a more conventional design using a steel tube encased in concrete. “It offered substantial economic savings resulting from changing the immersed-tube sections to a shallower rectangular configuration, thus reducing the scale of the steel fabrication,” says Fred Parkinson, Design Manager for Parsons Brinckerhoff. “The use of reinforced concrete in lieu of fabricated steel also significantly reduced the schedule risk for SKW, since tubes could be constructed without relying on specialized steel
The Second Midtown Tunnel measures 1,280 meters (4,198 feet) from portal to portal. The total length of the tunnel is 1,658 meters (5,441 feet) from end to end. It required digging a trench that is up to 29 meters (95 feet) deep below the
The tunnel is being constructed by piecing together 11 hollow concrete tunnel segments, averaging 106 meters (350 feet) long, 8.5 meters (28 feet) high, and 16.5 meters
SKW transported each 16,000-ton segment from the fabrication site at Sparrows Point, Maryland, 320 kilometers (200 miles) north of Norfolk, to the construction site. Six of the segments are now on-site, four of which have been placed within the dredged trench under the Elizabeth River. The five remaining sections will make the trek from Sparrows Point at intervals of about one a month starting
“The tunnel elements are towed through the Chesapeake Bay with all but about two feet of the segment submerged during transit,” Piper says. The trickiest part of the journey was crossing over one tunnel section of the Chesapeake Bay Bridge-Tunnel, then turning it nearly 360 degrees in the Atlantic Ocean in order to access the Norfolk Channel, then crossing over another tunnel section of the
When completed, the tunnel will feature bright, long-lasting, and efficient LED lighting, and will be the first Virginia tunnel to use an all-electronic toll collection system. The intelligent transportation system will include 60 closed-circuit cameras with automated incident detection capability and dynamic message signs along the
Under the P3 agreement, ERC will be responsible for management and operations of the roadway over a 58-year period. After that time, operations will be returned to VDOT.
The MLK Freeway extension will include a new trumpet-style interchange with Interstate 264, a partial diamond interchange with High Street, and bridge crossings through urban Portsmouth incorporating aesthetic and lighting improvements. The elevated roadway also crosses CSX Transportation’s
The extension will provide a limited-access connection between the MLK Freeway and I-264, which will reduce congestion on local Portsmouth streets.
“One benefit of the new freeway extension is that it will provide an alternative route for I-264 traffic when the Downtown Tunnel is congested or closed,” Piper says.
The tunnel project also required relocation and replacement of an existing 76-centimeter
“The City of Norfolk was a very willing partner,” Piper says. “The project essentially paid to replace an aging water line, and since they had a redundant raw water line to use during the replacement, service was not interrupted.” In early 2013, the relocation of 2,200 meters
There was a bit more reluctance from HRSD about the sewer line, since there was no re-route option, and an accidental puncture of the line could have severe environmental – and financial – consequences.
“We went through extensive effort to ensure we avoided the sewer line,” Piper says. “Dredging was completed without any issues and included a significant monitoring program. The sanitary force main was never out of operation.”
With substantial media coverage of the new tunnel, most locals are keenly aware of the project and its progress. Thus far, the reports have been favorable, and the project is currently
“It is a high-profile, well-scrutinized project,” Parkinson says. “Now that the tunnel and roadways are starting to take shape, people are really starting to take note of the improvements.”
“It’s such an important part of where we live, work, and play,” Piper adds. “I’m very proud to be a part of this historic project.”
For more about the Second Midtown Tunnel and the use of virtual design and construction on the project, see this month’s video.