For the past two years, Alexandrians and passing motorists couldn't really see construction of the new Woodrow Wilson Bridge as much as feel and hear it through the relentless pounding of pile drivers carving out a new foundation for the 12-lane span.

Now, the visual -- and inevitable traffic -- impact begins. This month, the Virginia Department of Transportation awarded a contract worth more than $54 million for work to begin in about two weeks.

A wrecking ball is gradually reducing one of the nine-story Hunting Towers apartment buildings along South Washington Street to rubble. This spring, the street will undergo a face-lift to accommodate widening the Capital Beltway as part of the bridge project.

Traffic on the thoroughfare will be reduced to one lane in the "off-peak" direction for the next two years as the overpass that crosses the Beltway is eliminated. The revamped Washington Street, expected to be completed in 2008, will still have four lanes but also a wide deck with pedestrian and bike paths and extensive landscaping.

The Washington Street project, which bridge officials hope will cause minimal disruption, is the first of several significant bridge-related projects:

* Work on replacing the rickety Route 1 interchange is scheduled later this year, adding more lanes and making merges less treacherous.

* Bridges will start rising this year over Cameron Run and Hunting Creek near Route 1, eventually connecting the new Beltway approach to the bridge with the current Beltway.

* Construction of the drawbridge part of the span over the Potomac River will begin this year.

Bridge officials said every effort is being made to minimize inconvenience to motorists.

"There's a commitment to keep all lanes open during peak hours of traffic on the Beltway," said John Undeland, chief spokesman for the $2.5 billion bridge project. "We've got a full-time 'lane guru' who coordinates all this."

For safety reasons, controlling dust from construction is a priority, too, he said.

Undeland said Beltway closures should be limited to late night. But on South Washington Street, one lane will be closed at all times for the next two years, and after a year's respite, one will be closed again in 2007 and 2008. Undeland said the middle lane of the remaining three will be reversible, northbound in the morning and southbound in the evening, and clearly marked with lighted signs.

"We've done traffic modeling, and it's not anticipated to have a big impact," Undeland said.

Residents in the remaining Hunting Towers apartments and adjacent Portovecchio apartments are somewhat skeptical.

"We are concerned with what's going to be happening in the next few years," said Phil Bradbury, a Portovecchio resident and member of a neighborhood bridge task force established by the city. "Obviously, there's got to be some traffic disruptions." But he added that project officials have been willing to work with neighbors in settling disputes.

The task force has identified access to Hunting Towers during construction as a potential problem. The two large buildings will no longer be accessible from South Street, and Bradbury said residents are concerned that left turns into its Washington Street entrance will be prohibited.

That would force southbound drivers to head farther down Washington Street and make a U-turn in front of Portovecchio's entrance, creating safety problems for residents of both buildings, he said.

Undeland said traffic at that intersection will be able to turn onto a service road parallel to Washington Street, rather than making a U-turn on Washington Street. He also noted that traffic there should be greatly reduced with demolition of the one Hunting Towers building and also of two office buildings and three garden apartments, all of which comprise 12 businesses and 337 apartments.

Ultimately, Undeland added, a left-turn lane will be installed.

Alexandria city officials are apprehensive.

"We're uneasy about Washington Street because that reversible center lane has serious implications as far as traffic flow around the city goes," said Reed Winslow, the city's coordinator for the bridge project.

Winslow said that having two lanes open in the peak direction should be adequate but that any problems could have a ripple effect on nearby arteries. "We know we're going to have to work to tune up our traffic control system," he said, adding that the city's relations with the bridge builders have been amicable.

Converting a congested six-lane highway with a drawbridge into a 12-lane highway with twin drawbridges is like "painting your car when you're driving 55 miles per hour," Undeland said. In addition to logistics, there are safety concerns, neighbors' concerns and environmental concerns.

Undeland said the project plans to spend $50 million on efforts to keep the water and air clean and maintain natural habitats.

Stephanie Spears, an environmental specialist with the project, said she regularly checks air and water quality monitoring stations on both sides of the river. In addition, wildlife has "adapted really well," she said.

Bald eagles have nested and reproduced on the Maryland side of the project and have been spotted snatching fish after launching themselves off the backs of tugboats working in the river, she said. Foxes are regular visitors to the various sites, and some river work has been shifted to winter months so as not to interrupt fish movement, she said.

Though the pong-pong-pong of pile drivers was a constant presence for much of last year, demolition of the Hunting Towers building has been much quieter, some neighborhood residents said. Project managers decided not to use explosives to bring down the building all at once.

Instead, a wrecking ball and crane-mounted grapples are being used to pull it apart gradually. Workers constantly hose the area to minimize dust, even in the biting cold, and Bradbury said the moves have helped to lessen complaints from neighborhood residents.

Winslow said that pile driving in the river on Sundays is the latest hot issue and that the city is trying to find a solution.

"Generally speaking, they've been quite cooperative, and we've been able to negotiate around these things," Winslow said. "I'd say the relationship is good."

When completed in several years, the Woodrow Wilson Bridge will have 12 lanes and twin spans. Soon, work begins in earnest on related road projects, such as revamping South Washington Street.