At a Boston City Council hearing this afternoon on connecting commuter-rail lines that now end at North and South stations, former Gov. Mike Dukakis had a simple message: "Please kill any further work on South Station expansion; it's totally unnecessary."

Dukakis was one of several speakers pushing to connect and electrify the rail lines that now dead end at the city's two main commuter rail stations at a hearing called for by at-large Councilor Annissa Essaibi-George. A link between the north and south sides of the commuter-rail system would let trains continue onto other destinations, rather than being forced to sit at the stations - or nearby rail holding areas, for example, in Widett Circle in South Boston and Readville in Hyde Park

All said that while the North/South Rail Link would cost billions, it would save the billions that would otherwise go to adding more tracks to the two stations - even without taking into account the increased economic opportunities from connecting residents on one side of Boston with jobs on the other and the savings from easing the region's worst-in-the-nation highway congestion, by getting more people on trains.

And, Dukakis and other speakers said, it would offer far more opportunities for expansion of the regional rail system while adding more tracks at two dead-end stations would have no more room for future expansion. Former state Rep. Businger of Brookine doubted South Station expansion could ever even happen, because it relies on the Postal Service moving its large Fort Point facility somewhere else, and the Postal Service has shown great reluctance in doing that.

Clay Schofield, who worked on north/south engineering studies under Dukakis, added it would make it far easier to maintain commuter-rail locomotives - 62% of which are on South Station lines, forcing them to take an arduous journey across the Charles River and through Cambridge streets to get to the T's locomotive repair facilities in Somerville.

Dukakis and Businger said the issues involved in actually getting the link built are far more political than technical. Schofield said the bulk of the work would fall on tunnel-boring machines deep underground - unlike with the Big Dig. He said London built 26 miles of new subway tunnels with almost no above-ground disruption.

Dukakis said the Baker administration, for some reason, is having "a particularly difficult time getting projects up and moving that are essential." They can't even spend the money they have appropriated, he said, adding "they've got to commit themselves to more than maintenance."

State Sen. Jamie Eldridge (D-Acton) , who has long advocated for the rail link, acknowledged some people are fearful of a second Big Dig, but said it's time for "bold vision for what's possible."

Dukakis and other speakers derided a report by a state-hired consultant last year that cited a potential $12.8-billion cost, saying the study foisted expenses onto the proposal that the state has to pay for anyway, such as new train cars and signals. They acknowledged that more work is needed to determine an exact cost. Businger said that any further studies should include the costs of doing nothing - in terms of congestion on both the rail systems and regional roads.

State Rep. Tami Gouveia (D-Concord) says we need to stop thinking that roads can just be built and paid for by the state while expecting public-transit projects to play second fiddle.