"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."