Next stop: low-cost diesel rail?

But what if there were some middle ground that could deliver some of the advantages of rapid transit on existing commuter rail tracks?

That's been a debate among state and local transportation planners for the past few years, and it recently received a bit of a boost from transportation secretary James A. Aloisi Jr. on his way out of office.

The concept involves using a type of train that is popular elsewhere in the world, but in fairly limited use in the United States. It has the type of name that only evokes glamour in the world of transit nerds: Diesel Multiple Unit, or DMU for short.

DMUs run on railroad tracks like commuter trains. But unlike commuter trains, they are self-propelled cars, meaning they do not have to be pulled along by a locomotive. That means the trains can pull in and out of stations more quickly and run smaller lengths at more frequent intervals. If you don’t need a locomotive to pull the train car, you can run more cars, and in smaller sets, using less fuel.

Instead of waiting 30 minutes or an hour between trains, one might wait 10 or 15 minutes for a DMU. The old Boston and Maine Railroad ran them almost exclusively in the 1950s and 1960s, said James O’Leary, a former MBTA general manager who is now a partner in the company that runs commuter rail under contract for the T. They fell out of favor in recent decades, but transit agencies have been showing increased interest in hopes of persuading American manufacturers to build them for domestic use, he said.

A few regions - South Florida, Southern California, New Jersey - have brought them back in recent years, but mostly in limited use.

For the past five years, the City of Boston has been advocating the use of DMUs for Allston and Brighton and Dorchester, using existing tracks.

“Right now, it’s really at a concept level,’’ said Vineet Gupta, director of planning for the Boston Transportation Department.

But if the idea took hold, Gupta envisions something that could run as far as Route 128 using the Worcester Line and continuing through the city, by the turnpike, linking up with the existing Fairmount Line into Dorchester, which is now being upgraded for better local service.

Aloisi, whose resignation takes effect at the end of this month, talked up the concept in two recent letters, one in August to state Senator Steven A. Tolman, a Democrat who represents Allston, and a second one this month to environmental secretary Ian Bowles. In the letters, Aloisi said that the state’s recent decision to purchase new rails from the CSX company opened opportunities to upgrade the lines and to use the DMU vehicles for urban service. In the Oct. 15 Bowles letter, Aloisi suggested the vehicles could go in another direction.

“This possibility has not yet been seriously analyzed, but in the aftermath of the CSX deal, serious consideration of DMU service . . . from East Boston to Allston Landing should be considered more fully,’’ he wrote.

Spokesman Colin Durrant, said Aloisi has advocated ideas like this to meet expensive long-term goals with short-term and midterm alternatives. He cited the recent addition of Silver Line bus service to South Station as an example of that type of thinking. It created a new transit link to the airport from Dudley Square without building a $2 billion tunnel that has faced tough funding hurdles.

It’s not clear whether Jeff Mullan, who takes over for Aloisi, shares his vision on DMUs. He said on Friday that it was premature for him to comment and that he is focused on merging the state’s road systems as part of a historic reorganization project. But he and Aloisi have spoken about the idea, he said. Durrant later added that it’s “not something we’re considering in the near future.’’

While it’s less expensive than a subway line, it’s not exactly cheap. The state would need to build additional tracks on some routes and upgrade existing rails. The cars are also costly. The six cars being used in South Florida as regular commuter rail vehicles cost the state $24 million for the set in 2003, more than conventional cars usually cost. And the prices have probably gone up since the 2003 purchase, said Bonnie Arnold, a spokeswoman for the South Florida Regional Transportation Authority.

There’s also a serious question of maintenance. The MBTA has what many specialists call the most complex network of transportation modes and equipment in the United States. And that complexity adds costs to a system that is already billions of dollars in debt. Operating yet another piece of new equipment - with new spare parts, new training, and new maintenance requirements - would require some serious analysis.

Transit riders movement

Legislators who signed up for the group want to help the MBTA out of its woeful debt and maintenance problems, according to an item that Representative Carl M. Sciortino Jr., a Somerville Democrat, posted on the liberal Blue Mass Group blog.

"We also need a coordinated effort in the Legislature to present a vision of what is possible long term, and to help make Massachusetts a leader in providing high quality, accessible, and affordable public transportation," he continued.

Municipal politicians can also play a role in the debate over how we get around. With that in mind, a group of green transportation advocates, led by the Livable Streets Alliance, has posted online results of a questionnaire for Boston City Council candidates.

It asks how often they walk, ride bicycles, drive, and use the T to get around. It also asks a lot of specific questions about what they would do to improve public transportation, as well as walking and bicycling access and safety, in the city.

Unfortunately, some candidates declined to respond to the survey, and others gave pat responses that failed to answer the questions. But several really did put some thought into interesting responses on issues that are vital to the life of the city. You can judge for yourself here: http://bostoncitycouncilelection.weebly.com

A discussion on discounts

Could that work in Boston?

The point of the proposal in New York does not seem geared toward raising money. Rather, it would be aimed at changing habits - getting people to ride during less crowded times - so subways can carry more people and use their trains more efficiently.

Boston, though a much smaller system, is facing similar capacity problems as New York over the next several decades. The heart of the system is expected to grow increasingly crowded and many expansion plans have been put on hold because the money is not there. If you've ever had your face crammed into someone else's armpit on a Green Line commute, you understand the issue.

So could Boston use economic incentives to reduce the rush hour crunch?

First, it needs to be said that trains and buses here do not currently run overnight, a frequent complaint of college students and 20-somethings. But what about discounts at other times outside of the weekday rush?

“We have a lot of excess capacity during off-peak hours. It would be wonderful to put people into those vehicles ,’’ said Brian Kane, budget and policy analyst for the MBTA Advisory Board, which represents cities and towns served by the T.

But Kane is not certain discounts could change habits dramatically here. Boston’s transit system is different than New York in that it is geared even more toward rush hour commuters, who would have a hard time changing their schedules, he said.

MBTA spokesman Joe Pesaturo said in an e-mail that the agency would not consider any changes to the existing fare structure until an outside review of the agency’s finances is complete. The review is expected out in the next week.

Correction: Because of an editing error, the Starts & Stops column in Sunday's Metro section included an incorrect Internet address for the site where readers can see the results of a questionnaire asking Boston City Council candidates how often they walk, ride bicycles, drive, and use public transit, as well as their views on a variety of transportation issues. The correct website is: http://bostoncitycouncilelection.weebly.com/the-survey.html.