Downtown Crossing, the project that city leaders hope will tie downtown to the city’s southern neighborhoods, received the Board of Aldermen’s approval Monday night.

The project will replace the Oak Street Connector portion of Route 34 with two urban boulevards connecting to Ella T. Grasso Boulevard. City administrators hope the project, which will cost the city $5 million, will provide an opportunity to continue a biotechnology boom in the Medical School district and a source of additional tax revenue. At the Board of Aldermen meeting Monday night, 24 aldermen voted to approve the project and one voted against approval.

“The next few years have to be all about jobs and tax base expansion, and this project will allow those things to happen,” Mayor John DeStefano Jr. said Tuesday.

At Monday’s meeting, Ward 7 Alderwoman Frances “Bitsie” Clark delivered a defense of the plan, which Ward 30 Alderman Darnell Goldson said was not in the interest of the city’s fiscal health.

“That we have a chance to heal the scar in the middle of our city, which has cut people off from downtown for decades, is one of the most exciting things that could happen,” Clark said.

Goldson, the lone “no” vote, offered two failed amendments at the meeting. The first amendment offered would have delayed the vote until the city raised money to fund its $7 million portion of the project’s funding. The second would have mandated a guarantee that any bonding on the project be paid back to the city within five years.

“During the last budget we agreed to reduce capital expenditures to manageable levels,” Goldson said. “We have not done that, and now we’re about to add to that debt.”

But Ward 10 Alderman Justin Elicker FES ’10 SOM ’10 said the future tax revenue from the new economic development enabled by the project will be significantly greater than the cost of the initial investment.

Ward 5 Alderman Jorge Perez agreed that the proposal will generate future economic growth.

“We don’t need a crystal ball to see that the area is going to grow because of medical center development that is going to happen there,” Perez said, adding that the project would not impact this year’s fiscal situation as the city’s first payment comes in the following fiscal year.

When Route 34 was built in the 1950s, it was part of then-mayor Richard C. Lee’s urban renewal project. But funds ran dry before construction was completed and for half a century it has been considered a central obstacle to downtown’s development.

DeStefano said the highway, which begins at Interstate 95, has cut the city off from the harbor and Union Station and hindered business downtown for decades.

Malley’s department store shut down in the ’80s, Macy’s closed in the ’90s and the Chapel Square Mall on Temple Street was converted into apartments in 2002 in large part because the highway reduced foot traffic, DeStefano said.

“Tonight’s vote was an important step in correcting one of Mayor Dick Lee’s most infamous mistakes in the history of New Haven’s urban planning,” said Ward 1 Alderman Michael Jones ’11, who voted in favor of the proposal. “I look forward to working with the community and city officials in the coming months to ensure that this project continues to move forward in a responsible manner.”

The city was awarded $16 million in federal TIGER II grants to fund Downtown Crossing in October of this year. Construction on the project is expected to begin sometime next year and reclaim as much as 11 acres for development.