"Wonderful. It's going to alleviate all this traffic. It's going to be great," a driver told CBS Radio station WBZ-AM.
The reopened ramp funnels drivers south of the city toward Logan International Airport through the eastbound Ted Williams Tunnel. The ramp was closed after tons of concrete panels fell from the ceiling in a nearby connector tunnel July 10, crushing a passing motorist.
Gov. Mitt Romney declared the ramp to be safe at a news conference on Tuesday before the midnight reopening.
But he cautioned that plenty of work remains in other tunnels closed since the accident and problems continue to come up as engineers review the safety of the tunnel network.
"Is there going to be more work done? Absolutely," Romney said. "But I feel very confident when I walk through (Ramp A). I'll feel more confident when I'm driving through it. It's a lot safer than a lot of other things we do. And I feel that Ramp A is safe."
The newly reopened Ramp A represents only about 10 percent of the total area of the Big Dig tunnels and ramps that have been shut down since 39-year-old Milena Del Valle was killed.
Other tunnel sections closed after the accident could take months to inspect and reopen, Romney said.
Meanwhile, state Treasurer Timothy Cahill said the Big Dig budget has a $133 million deficit after a freeze in federal highway funds. The Federal Highway Administration froze $81 million last year, saying project managers needed to explain how they would fix tunnel leaks. The Turnpike Authority then spent another $52 million on the assumption it would get federal money, but hasn't, leaving the $133 million hole.
In a letter to Romney, Cahill also said spending on the project could siphon funds from other public works projects, and also suggested the Big Dig's final price tag could exceed the estimated cost of $14.6 billion, The Boston Globe reported. Cahill asked Romney to explain how the state will cover the project's cost, including repairs and a "stem to stern" review.
Romney spokesman Eric Fehrnstrom said if financing problems are found, Romney would disclose the problems and work to solve them.
With Wednesday's ramp reopening, traffic enters the Ted Williams Tunnel eastbound to the airport from a surface bypass road in South Boston. The eastbound tunnel had been open only to buses, while other traffic has been diverted to older airport tunnels that cannot accommodate some trucks.
"This makes a huge difference," Romney said. "Both directions, eastbound and westbound, will now be able to have cargo trucks going in both directions, automobiles can go both directions."
The Federal Highway Administration and Office of Inspector General at the U.S. Department of Transportation said the decision to reopen was the result of a thorough inspection of tunnel repairs and "the state's implementation of an aggressive plan to monitor the reopened areas."
Since the accident, authorities have focused on the bolt-and-epoxy system that failed to hold suspended ceiling panels in place where Del Valle was killed. Inspections have revealed slippage in dozens of other tunnel locations, and workers have been reinforcing potentially weak connections.
Romney said Tuesday that inspectors over the weekend also discovered that brackets used to connect the panels to the ceiling weren't big enough, and workers had to replace 23 brackets.
The governor also criticized Big Dig project manager Bechtel/Parsons Brinckerhoff for not having noticed earlier that the brackets being used by contractors was not sufficient.
"The basic system had an area of flaw that hadn't been identified before," he said. "It's hard to understand how it is that the engineering firm responsible for the integrity and quality assurance of the entire project would not have done a calculation of these connector brackets and determine that they did not meet the specifications that had been set for this project."
Romney said it raises "very serious concerns about the oversight by these engineering firms of this project."
He said he would refer the company's role in the inspections to those conducting criminal and cost-recovery investigations, reports WBZ's Lana Jones.
"How can it be that oversight was so lax?" Romney asked.
Bechtel/Parsons Brinckerhoff stood by its work.
"We firmly believe the projects processes for engineering, construction and quality assurance were appropriate and robust," the company said in a statement. "We are proud to have been a part of one of the largest, most complex, and technically challenging projects ever undertaken in an urban setting and which already has transformed Boston into a more livable, attractive, and economically vibrant city."
The Big Dig highway project buried the old Central Artery that used to slice through the city, creating a series of tunnels to bring traffic underground. Although it's been billed an engineering marvel, the most expensive highway project in U.S. history also has also been plagued by leaks, falling debris, delays and other problems linked to faulty construction.
State and federal criminal investigations are under way to determine if construction failures are the result of criminal negligence.