THE steam-belching dinosaurs lumber over a primeval landscape of mud and dirt. These massive bulldozers, steam shovels, and trucks have transformed a pier-side parking lot beyond recognition: Where once hundreds of cars were parked, today there are towering mounds of dirt and yawning holes in the ground.
Before long, "Subaru Pier" - a former arrival point for the Japanese automobiles - will undergo an even more dramatic makeover. Once the concrete is poured and the walls have been constructed, this mud lot will become an entrance to a tunnel running through the polluted depths of Boston Harbor.
The construction going on now at "Subaru Pier" is the first phase of what state transportation officials say is the largest public works project currently under way in the United States.
The official name for this endeavor is the Central Artery/Third Harbor Tunnel Project, but Bostonians call it the "Big Dig." And big it is, in every sense of the word: The project will cost federal and state taxpayers a stunning $5.8 billion, employ about 5,000 people, and take a decade to complete.
The rationale for this sweeping construction effort is simple: Downtown Boston has some of the worst traffic gridlock in the country. A two-mile stretch of Interstate 93 (I-93) running through the heart of downtown is constantly choked with cars. So are the two tunnels that carry traffic between Boston and Logan International Airport.
"If we do nothing, the existing central artery will be jammed up for 14 to 16 hours per day in 2010," says Project Manager Peter Zuk. "That's clearly unacceptable both from the transportation point of view and from the air quality point of view."
Besides the nightmare of nonstop traffic jams, there is an equally compelling aesthetic argument against I-93: Its elevated structure is an eyesore that cuts downtown off from the waterfront and separates Boston's North End from the rest of the city.
The Big Dig is an attempt to remedy some of these problems. The project will construct a third harbor tunnel, doubling the traffic capacity from downtown to the airport. It will also tear down the elevated portion of I-93 and replace it with a depressed roadway beneath the existing route.
Once it is finished, sometime around the year 2000, the Big Dig will have transformed the environment of Bean Town's waterfront area. The elevated roadway that casts a gloomy shadow over a wide swath of downtown will be replaced by 27 acres of parkland. Bicyclists and pedestrians will roam where cars sit bumper-to-bumper today.
Some environmentalists see this as an example of urban beautification the rest of America should follow.
"There's no doubt about it - Boston will be a more pleasant city to live in," says Robert Zimmerman, executive director of the Charles River Watershed Association. "The quality of life in a city is determined by its open space."
But not everyone here shares that sanguine assessment. In fact, ever since plans for the Big Dig were unveiled in 1983, it has run into a wall of almost unrelenting opposition from various parts of the community.
Fishermen have been concerned that blasting in the harbor would damage lobster traps. Vendors in the North End's centuries-old Haymarket, adjacent to I-93, have worried that construction would ruin their livelihood. Almost everyone in Boston has been fretting that tunnel-digging would bring swarms of rats out of the sewers and onto the streets - which actually occurred in the 1950s when the second harbor tunnel was constructed.
State officials have gone to mammoth lengths to assuage these concerns. The Big Dig has an extensive rodent-control program, supervised by a staff biologist. The project also has a $250,000 machine that emits sonic waves to keep migrating fish away from underwater blast sites. And there is a full-time staff archaeologist to make sure construction work does not destroy any mementos of Boston's historical past.
Many environmentalists originally were skeptical of plans to increase Boston's road capacity, which they feared would only increase the number of cars on the road. A number of groups, led by the Conservation Law Foundation (CLF), sued the Central Artery project on the grounds that the increased traffic would violate federal environmental standards.
In March, however, the CLF and most of the other plaintiffs reached out-of-court settlements with the Massachusetts Highway Department, which is building the roadway mainly with federal dollars. State officials agreed to take certain measures to "mitigate" the project's impact on local traffic - such as setting aside carpool lanes and limiting parking in downtown Boston.
"The state is committed to extraordinary measures to keep highway volume down," says CLF attorney Stephen Burrington. "We think some highway expansion is warranted by the truly extraordinary level of congestion here. It doesn't get any worse than this."
But the Sierra Club and the National Association of Railroad Passengers are pressing ahead with lawsuits against the project. The suits contend not only that the Big Dig would add to traffic congestion, but that it would also further pollute Boston's already-foul air.
"We think it's a disastrous project as currently designed," says Louise Lewis, a Sierra Club spokeswoman. "It'll attract more cars, more air pollution, and more congestion.... We'd like to see a rail project instead."
Yet another obstacle in the path of the Big Dig was a groundswell of community opposition against plans for constructing a looping, elevated highway interchange linking the new artery with US Route 1 in neighboring Charlestown. State officials recently abandoned the plan, known as Scheme Z, and agreed to build a less obtrusive interchange in which much of the traffic will go through a tunnel instead of an overpass.
Thanks to the compromises over "mitigation" measures and Scheme Z, the wind has gone out of the sails of local opposition - and construction has finally started on the Big Dig.
Since early this year, workers have been scooping out a trench through Boston Harbor and tearing apart "Subaru Pier" on the shoreline. The tunnel, expected to open in 1994, will be the first part of the Big Dig to be finished.
Once the tunnel is completed, work will start on the depressed Central Artery. Even before it has begun, that part of the project has run into considerable difficulty. In late June, state officials announced that the depressed road was two years behind schedule and $600 million over budget.
Project managers say that most of the delays and cost overruns are due to their willingness to make changes on the project designed to satisfy the concerns of environmental and community groups. For example, redesigning the Charles River interchange will be more expensive than simply building Scheme Z.
Despite those obstacles, state officials are confident that the Big Dig - which they describe as the last link in America's interstate highway system - will be completed by the turn of the century.
"The project is gathering momentum in both construction and in forming a consensus that it ought to be completed," Mr. Zuk says. "I'm very happy the project has been progressing as well as it has."