Manhattan Borough President Gale Brewer is calling on DOT to study making 14th Street a bus-only thoroughfare while L train service is disrupted during Sandy-related repairs.

To allow for urgently-needed fixes to the L train tunnel, the MTA is considering either a full shutdown of service between Bedford Avenue and Eighth Avenue for 18 months, or a three-year variation that preserves about 20 percent of current service. At a press event this morning, the Riders Alliance revealed that most L train riders who responded to an online survey prefer to get it over with in 18 months — a position the MTA seems to share.

In either case, said Riders Alliance Deputy Director Nick Sifuentes, the city and the MTA need to take steps to keep people moving: “No matter what the MTA does, a shutdown will profoundly change transportation options for commuters on both sides of the East River.” Sifuentes said survey respondents “called broadly for robust, supplementary bus service in Manhattan and Brooklyn.”

In the survey, respondents suggested bus lanes in both Brooklyn and Manhattan and along the Williamsburg Bridge, as well as a number of other measures, including Citi Bike expansion, more capacity for bicycling on the Williamsburg Bridge, increased service on nearby subway lines, and increased ferry service.

“The shutdown will not be easy, but a robust set of alternatives would reduce the pain,” said Kate Slevin of the Regional Plan Association. “For example, 14th Street could become reserved for buses, pedestrians and bikes, and the Williamsburg Bridge could offer dedicated bike and bus routes. The MTA and DOT need to be bold.”

Brewer said the city and MTA need to put all options on the table for the sake of people and businesses on both sides of the East River. “Most importantly, we need a bus-only lane in each direction from the length of the Manhattan L train corridor,” she said.

Brewer did not explicitly endorse further steps but said the city has to consider every possibility. “What they need to do is a study quickly because whether it’s bus lanes, whether it’s a shutdown, obviously the current situation will not work because it’s jammed up, particularly [during] rush hour,” she said.

Officials have said that L train repairs will begin in 2019, which leaves enough time to implement car-free rights of way for buses and bikes in Manhattan and Brooklyn — if DOT and the MTA start making preparations soon.

Making 14th Street car-free to allow for robust surface transit has the support State Senator Brad Hoylman. Last week, the Daily News reported, Council Member Corey Johnson asked DOT Commissioner Polly Trottenberg about the concept, which he called “a good thing to look at.”

Trottenberg didn’t rule it out. “Everything is going to be on the table,” she said.