When New Yorkers go to the polls less than a year from now, they’ll definitely be voting for a new mayor, and they might also be voting for billions in state-backed transportation funding, if a measure put forward by Assembly Member James Brennan clears Albany.

Brennan, a Brooklyn Democrat representing Park Slope, Windsor Terrace, and Kensington, is reintroducing his bill for a $4.5 billion statewide transportation bond, evenly split between roads and transit. Starting in January, he’ll be making a push to sign up additional Assembly co-sponsors (there are now 16, all Democrats), and to find a sponsor for a Senate companion bill, with an eye toward recruiting Republican support.

“When we put it out there last year, we had no intention of passing it,” Brennan legislative director Lorrie Smith explained, saying that they wanted to begin circulating the issue in Albany before making a push in 2013. “We’re taking the next step and trying to fashion a proposal that will go before voters in November.”

Some of the bond money is expected to go to the MTA’s next five-year capital program. Although that slate of maintenance and expansion work is still undefined (the current capital program runs through 2014), it’s likely this time around that keeping the system’s existing infrastructure in a state of good repair will be a higher priority than big-ticket projects like the 7-train expansion.

“We’re going to have to find different sources of revenue in order to find the capital necessary to sustain a state of good repair,” MTA Chairman Joe Lhota said earlier this year.

Although advocates welcomed the bill’s reintroduction, they cautioned that it is by no means a complete fix, for either the MTA or the state’s larger transportation system, which both have tens of billions of dollars in unfunded needs.

“We remain a little concerned that this might pass and voters and legislators might think that our funding needs have been resolved when, in fact, they have not,” said Tri-State Transportation Campaign Executive Director Veronica Vanterpool. Separately, both Tri-State and Transportation Alternatives said that Brennan’s proposal should be part of a larger revenue plan. Brennan himself said in April that the bond issue would still leave a hole of at least $6 billion in the capital program, even with federal matching funds taken into account.

While a more ambitious legislative package would address a heftier chunk of the MTA’s funding needs, it would also be tougher to enact.

“Brennan at the moment is the only game in town” because he’s “proposed something other than agency borrowing,” said Gene Russianoff of the Straphangers Campaign. The Brennan bond would be backed by general tax revenues, unlike much of the borrowing for the current capital plan, which is paid for out of the MTA’s operating budget. Moving borrowing from the MTA’s books to the state’s can take pressure off straphangers, who, absent initiative from Albany, are paying for debt service through fare hikes.

Even with this bond issue, MTA debt service is on track to keep growing, and that’s before factoring in the agency’s extra borrowing to repair Hurricane Sandy damage that is not covered by insurance or the federal government.

The bill is similar to the transportation bond issue voters approved in 2005, which provided an inflation-adjusted $3.42 billion split between roads and transit. But the funding mix isn’t the only similarity. “It’s intended for the ballot in the fall under the theory that a big turnout of city voters would help, which was the case for the 2005 bond act,” Russianoff said. “The timing seems to be politically well thought-through.”

A transportation bond on the ballot in 2000 — a year with no mayoral election — failed despite a wide margin of support in New York City.

But before voters have a say, the legislature and Governor Cuomo must approve. “We would love to interest the governor and hear about it in his State of the State, but we have no idea if that will happen,” Smith said.

“I’m upbeat about Brennan being able to make this issue one that gets on the legislature’s top agenda,” Russianoff said.