Commuters at South Station would have direct access to North Station via a North/South Rail Link if former Gov. Michael Dukakis gets his way.

Michael Dukakis knows something about defeat. And now the failed presidential candidate appears to be on the losing side of another campaign.

The former Massachusetts governor is advocating a link from Boston’s North and South stations that would remove thousands of cars from the region’s highways and make travel more convenient. But the idea is going nowhere.

“It’s a hell of a lot more important than spending $1 billion on a one-mile Silver Line bus tunnel under the city of Boston,” said Dukakis about Phase III of the city’s rapid-transit bus line, which calls for an underground passageway with a portal at Charles and Tremont streets. “The North/South link is affordable and doable and I’d like to see us get cracking on it.”

A tunnel connection between the two major transit hubs would unite a pair of commuter rail systems operated by the MBTA, one that stops at North Station and another that ends at South Station. The connection also would allow Amtrak’s Acela high-speed rail service to extend through Boston to benefit travelers from Maine, New Hampshire, Vermont and Canada.

Today, passengers traveling from Hingham to Ipswich must board the commuter rail’s Greenbush Line in Hingham; then travel to South Station, in order to take the subway to North Station; then board the Newburyport/Rockport Line to Ipswich.

“I think that’s crazy,” said Dukakis. “Can you imagine if rapid-transit lines operated that way? No one would stand for it. But that’s what we’ve got here.”

The idea for a North/South Rail Link was identified as a priority in the 1960s by the Boston Transportation Planning Review. In 1993, the Central Artery Rail Link Task Force appointed by then-Gov. William Weld issued a 70-page report that confirmed the link’s feasibility with an estimated cost of $1.74 billion. Construction of the Central Artery/Tunnel Project, or Big Dig, was planned with the possibility of a link in the future. From 1995 to 2003, Amtrak and the Massachusetts Executive Office of Transportation and Construction developed an investment study and a draft version of an environmental impact report.

But the idea has lost momentum. The state’s crumbling infrastructure and other public transportation needs, including the Green Line extension to Somerville and the new commuter rail to New Bedford and Fall River, have taken priority.

“Given the lack of money to repair the state’s roads and bridges at a cost of $20 billion and a host of other planned transit projects, the link is a tough thing to consider right now,” said Wig Zamore, a founding member of the Mystic View Task Force, a Somerville-based advocacy group.

‘A Fresh Look’

Transportation advocates are reluctant to criticize any project that would remove vehicles from congested Bay State roads. But privately they say that the North/South link should be less of a priority because the commuter rail has dramatically fewer riders than the MBTA’s other lines.

While there are 78,150 daily round trips on the commuter rail including the new Greenbush line that opened this week, the Red, Blue, Orange and Silver lines transport nearly 675,000 riders daily, according to MBTA data.

Erik Abell, a spokesman for the state Executive Office of Transportation and Public Works, said in an e-mail that while the Patrick administration recognizes that the North/South project could benefits the traveling public, funding sources have not been identified.

“When the Patrick administration came into office, we wanted to take a fresh look at the project and began a dialogue with stakeholders,” Abell wrote in his e-mail. “There are no identified sources of funding yet Â… Should full federal funding become available to advance the planning stage, we would strongly consider advancing that process.”

In April, Gov. Deval Patrick vowed to bring passenger rail service to the South Coast by 2016. The South Coast Rail project would extend passenger rail transportation from South Station to Fall River and New Bedford. The announcement came 20 years after a string of Massachusetts governors promised the residents of southeastern Massachusetts access to the transit system that would connect the cities and towns of eastern Massachusetts.

The administration pledged an initial bonding commitment of $17.2 million toward the $1.4 billion project. Still, Patrick noted that new revenue sources would be needed to pay for the full cost of the project. At the time, the governor did not mention the North/South link.

But Dukakis, a Northeastern University professor, insisted the link would pay for itself. He said up to two-thirds of the cost would be generated as a result of “significant savings” derived from not having to stop trains at each terminal and turn them around.

“This project will also dramatically increase revenue because it will take 60,000 cars off the roads,” he said. “There are an awful lot of people these days who are driving because they just refuse to get off at North Station or South Station and have to transfer to another line to reach their destination.”

Still, after a decade of inconvenience due to the Big Dig, which saw its budget soar from $2.8 billion in 1985 to over $14.6 billion in 2006, is the public ready for a Little Dig?

“When I was governor and Fred Salvucci was transportation secretary, we tunneled a Red Line extension from Harvard Square to Alewife 100 feet below the surface on time and on budget with a minimum of disruption,” Dukakis said. “The Callahan Tunnel was done in 24 months. The Big Dig was sheer incompetence.”

Dukakis is not alone in his steadfast support for the North/South link. The Sierra Club, a nonprofit group whose mission is to protect the environment, is a major backer.

Club members argue that the connection would remove thousands of commuters from the state’s highways. Environmental studies for the project show that the connection will result in the largest time savings of any transportation project in Massachusetts, and create cleaner air by eliminating more than 582 tons of the global warming gas CO2 daily, the advocacy group noted.

In addition, the Sierra Club vows that building the North/South Rail Link project would create the infrastructure for an efficient, convenient rail service that offers attractive transportation options for local commuters and passengers traveling throughout the Northeast. Its members say it would enhance the federal investment made in Amtrak’s Northeast Corridor because continuous interstate and intercity rail service would be available along the East Coast for the first time.

“Boston will be one of the great megalopoli over the next 50 years and the single-most important investment in this region’s economic future would be a high-speed rail system from Maine to Virginia. There’s no question about that,” Dukakis said. “The link is an important part of that.

“I think our chances working with the 12 New England states and the District of Columbia are very good. It sure beats spending $4 billion a week in Iraq.”