Life in the Express Lanes on the D.C. Area I-95 Project
The term "express" has a dual meaning on the 95 Express project in northern Virginia. For the more than 200,000 vehicles that travel the 29-mile stretch of Interstate 95 south of the Capital Beltway every day, the project, to be completed in early 2015, aims to relieve congestion and speed traffic flow. For engineers and construction crews, the goal is to expedite delivery of the $1-billion project built right in the middle of a heavily traveled artery.
The project will convert 20 miles of the highway's existing 40-year-old, dedicated high-occupancy vehicle (HOV) lanes south of the Beltway into dynamically tolled lanes available to all motorists willing to pay. It also will widen 14 miles of existing HOV highway to three lanes from two and carve nine new miles of similarly reversible roadway out of the highway's median.
The Express Lanes project's multiple tasks had to be planned, designed and built in a limited-access corridor and within a 28-month schedule that began almost immediately after the ceremonial groundbreaking shovels were put away on Aug. 7, 2012.
"From the first day of construction, everything has been focused on being ready for the first day of tolled operations," says Walter Lewis, project director for Fluor-Lane 95 LLC, the design-build contractor for the Transurban-led consortium that secured private financing for the project. The consortium will operate and maintain the system under a 75-year contract with the Virginia Dept. of Transportation (VDOT).
Northern Virginia highways are familiar turf to the Transurban/Fluor Corp.-Lane Construction Corp. joint venture. The team was wrapping up a $1.4-billion, 14-mile toll lane project on the western side of the Capital Beltway when the 95 Express Lanes job began. When completed, the two projects will connect at the Springfield interchange.
Indeed, speed was so critical for the project that the cycle of design-package development and client review was under way as the public-private-partnership financing structure was being made final. "By the time the packages were formally submitted, they were close to 100%," says Richard Prezioso, Transurban deputy project manager. "Our joint work groups had been going through the plans as they developed, so we had pretty much agreed on the big decisions."
Time-sensitive transitions
The existing HOV lanes gave the 95 Express Lanes team a ready-made footprint, but they were far from ready for their new purpose. "The upgrades required much more than simply repaving and adding signs," says Dan Papiernik, mid-Atlantic toll services leader for lead designer HNTB.
Besides widening 14.1 miles of the HOV lanes, existing concrete barriers on the existing section had to be demolished. Cast-in-place protective structures and guardrails with foundations for signs, lighting and tolling gantries had to be installed. Infrastructure to support the tolling system also had to be put in place, including more than 1.5 million linear ft of conduit and 3.7 million ft of cable and wire.
What's more, all of this work had to be carefully managed to meet VDOT's mandate that the existing HOV system be available to carpoolers during normal rush hour periods.
"There was also an educational component to the design as the HOV lanes have been associated with a specific use for decades," Papiernik says. "Now being available to all drivers, we had to make signage and access points as clear as possible so that motorists can easily and safely make decisions as to whether to use the lanes at all and how far they want to travel on them."
To support this activity, the team used the VDOT-owned right-of-way along the route as material and equipment laydown space. That included areas under the I-95/395/495 "Mixing Bowl" flyovers near the Express Lanes' northern end and several interchange loop interiors.
"Once the HOV lanes closed for the night, we could shuttle materials to where they would be needed," Lewis says. "Sometimes, fill dirt had to be moved two or three times to get it to the right place."
The most complicated work took place at the median access ramp for the Springfield-Franconia Parkway overpass. It had to be widened by as much as 10 ft to safely accommodate new traffic flows while remaining available for HOV users. That meant sandwiching the existing retaining wall supporting the ramp with custom, mechanically stabilized earth (MSE) structures framed by post-tension strands attached to more than 310 steel piles.
More than 50,000 sq ft of MSE panels attached to the vertical posts provide an exterior finish for the structures, which rise as much as 35 ft from the median to the parkway.
Although the nine-mile-long greenfield construction area between the existing HOV southern terminus and State Route 610 in Stafford County was pinched on each side by I-95's general-purpose lanes, work proceeded virtually nonstop.
About 1 million cu yd of fill dirt and drainage upgrades were needed to shore up the Potomac clay formations in the median and grade foundations for the travel lanes, slip ramps and new 448-ft and 542-ft continuous-segment flyover structures that join I-95's southbound lanes. Five new bridges, ranging in length from 159 ft to 313 ft, were added as well.
Safety amid the scramble
The project team has focused as intently on safety as on the schedule. To ensure consistency through the project, all subcontractors were required to undergo Fluor-Lane's safety orientation training as well as their own programs. The team also worked with VDOT to develop one-way construction area entrances/exits to ease trucks safely in and out of mainline traffic.
Through nearly 3 million work hours, the project's incident rate is 0.48—well below the Occupational Safety and Health Administration national average of 3.6.
The 95 Express Lanes project also boasts the second-highest level of participation by disadvantaged business enterprises (DBEs) and small and woman- or minority-owned (SWaM) firms for Northern Virginia transportation projects, with nearly $193 million committed to more than 130 qualified subcontractors, exceeding the $189-million initial goal. Only the I-495 Express Lanes ranked higher, VDOT says.
With the I-95 Express Lanes nearly 75% complete as of July and heavy construction all but done, the focus has shifted to completing the installation of more than 50,000 linear ft of sound walls to protect neighborhoods adjacent to I-95's right-of-way. Other priorities are paving and finishing barriers, guardrails and stormwater management systems.
The project team also is getting a head start on closing out the project's completed elements. "That's one of the valuable lessons learned from I-495," Prezioso says. "There'd just be too much to do if we waited until everything was finished."
Also being readied are the tolling gantries, cameras, traffic-management equipment and other systems that will tie into Transurban's joint I-495/95 operations center in Springfield. More than 900 devices will combine to monitor traffic speed, congestion and incidents in the express and general-purpose lanes, updating the toll pricing system with new information every six minutes.
Completion of Northern Virginia's Express Lanes network is now just months away. That milestone will bring to a close nearly eight years of continuous highway construction since the I-495 project began in 2008. VDOT program manager H.S. Warraich observes that, compared with the five-year I-495 project, "I-95 has moved at warp speed."
