By Steven Ginsberg
Washington Post Staff Writer
Thursday, July 13, 2006; A01
In a fitting final tribute to one of the most infamous traffic bottlenecks on the East Coast, one last dashboard-pounding jam is likely to occur this weekend at the old Woodrow Wilson Bridge as southbound motorists are shifted onto the new span.
The last driver to cross the decaying 45-year-old structure will probably do so Saturday, at the midpoint of a weekend of backups that will begin at 8 p.m. tomorrow when the inner loop of the Capital Beltway is reduced to a single lane so it can be realigned with the new bridge.
Outer loop traffic was switched onto the new span last month and, despite dire warnings, the work caused few delays. But project officials said the inner loop poses many more problems and ask drivers to take other routes to avoid hours-long jams.
Project spokesman John Undeland said outer loop delays were largely avoided because Interstate 95 drivers were diverted to the western side of the Beltway at Springfield. But a similar detour is not feasible for the inner loop because so many major roads connect to the eastern portion of the Beltway in Maryland, he said.
He also worried that drivers would suffer from "message fatigue" and not take the warnings of major backups seriously, especially given how few delays occurred last month.
"We don't want people to look at the last switchover in June and say, 'Hey, that was a piece of cake,' " Undeland said. "We have a different situation here. This is all going to rest on whether people hear and heed the message."
A similar set of weekend-long delays occurred last summer. The outer loop shift caused few problems then. But traffic backed up for as far as seven miles, and delays lasted as long as three hours when work was done on the inner loop.
To switch from old bridge to new, workers will redirect the Beltway and add as much as 36 inches of asphalt to align it with the new bridge.
To give them room to do so, the inner loop will be limited to a single lane for four miles, from the Route 210 interchange in Maryland to the Route 1 interchange in Virginia. Even after the switch is made Saturday, the highway will remain one lane while work continues.
The ramp from the southbound lanes of Interstate 295 to the inner loop will close tomorrow night, and the ramp from the inner loop to Route 1 will close Saturday.
Project officials hope to open all three inner loop lanes of the new bridge and both interchanges Sunday, but they said delays could last until 5 a.m. Monday.
Bridge officials advised drivers to take the western half of the Beltway, Route 301 through Maryland or Interstate 395 through the District to avoid bridge traffic.
Once all traffic is shifted onto the new bridge, workers will begin almost immediately to take the old one apart so a second span can be built in its place.
The section stretching over Jones Point Park in Alexandria will be the first to go and will be followed by the portions that stretch to the drawbridge. That work is expected to be finished by this fall. The expanse between the drawbridge and the Maryland shore will remain as a staging area for construction of the new bridge until late 2007.
The deck of the old bridge will be broken into pieces and removed by excavators with hydraulic jaws called "munchers." Pier columns and the bridge abutment will be chipped away by hoe rams -- large jackhammers attached to the ends of excavators. And the underwater portions of the piers will be detonated and scooped from the river bed.
The real fireworks will come on a single night late next month when dozens of steel support beams on the Virginia side will be detonated at once and are expected to drop to the ground in a crash that project officials said will resemble a nearby lightning strike and thunderclap. Knocking down the beams will require closing the Beltway for about 30 minutes, so the event will take place about midnight.
"This is not a bump in the night," said Undeland, adding that the date will be widely advertised when it is known.
The rest of the demolition will be done between sunrise and sunset Monday through Saturday beginning next week, Undeland said. In all, 1,000 tractor-trailers' worth of debris will be removed. Project officials also said they plan to use significant portions of the demolished bridge as fish reef in the Chesapeake Bay as part of a Maryland state program.
Officials want to open the second span in two years. When it is done, the Wilson Bridge will have doubled in size, from six lanes to 12. Regional transportation officials hope that will be enough to relieve the area of some of its worst congestion.
The $2.44 billion bridge project also includes upgrading several interchanges in Virginia and Maryland to increase capacity on the Beltway and to accommodate the additional bridge lanes.
Most of those projects will be finished by the time the second span opens. But improvements to the Route 1 interchange will not be completed until the middle of 2009, and the Telegraph Road interchange will not be finished until late 2011.