L train riders prefer a full service shutdown if it means repairs will get done faster.

According to a new Riders Alliance survey, 77 percent of New Yorkers living along the line favor an 18-month, complete closure of L train service into Manhattan to allow for the MTA to make Hurricane Sandy-related repairs on its Canarsie tubes.

It’s one of two timeframes the MTA is currently exploring for the work. The other, less popular option, would bring a three-year partial shutdown that would maintain L service at 20 percent capacity.

“I think it’s kind of like ripping a Band Aid off,” said Nick Sifuentes, Riders Alliance deputy director, on rider preferences. “People know a three year closure at 20 percent capacity will not work for anybody. If this going to happen do it quickly and well.”

Riders Alliance plans to officially endorse the 18-month closure option at a press conference on Tuesday. The transit advocacy group polled 350 Alliance members online and has sent a letter to the MTA asking the agency to consider rider preferences in its decision making.

Whichever option the agency chooses, advocates say robust mitigation efforts will be needed to keep commuters moving along an already crowded line.

“On a good day, the L train is nearly filled to capacity whenever I leave for work, be it 7:30 or 10:00 in the morning. When there is even a minute delay, the trains are packed, uncomfortable, and slow,” said Alexis Saba, Alliance member and L train rider, in a statement.

About 225,000 L train riders take trips under the East River each day. To keep them moving, advocates say the agency needs a robust, multifaceted approach to mitigation.

“The availability of alternatives to L service will be what makes either option a success,” said MTA Board Member Andrew Albert.

During the shutdown, the MTA says service will be boosted along the neighboring J, M and G lines. The agency will run full-length G trains to increase service along the line by 160 percent. Shuttle buses over the Williamsburg Bridge and Select Bus Service for crosstown Manhattan trips would also be added.

There were popular requests among those surveyed: the MTA should also consider service increases along the A, C and Z trains; dedicated bus lanes should be in place along 14th St. in Manhattan and along the Williamsburg Bridge; and there should be an expansion of Citi Bike and dedicated bike lanes over the Williamsburg Bridge.

“We need MTA and Department of Transportation to be really aggressive about these options,” said Sifuentes.

The MTA plans to announce a decision on shutdown options by July.

“The MTA is in the midst of an aggressive community engagement process and we welcome all public input about the pros and cons of the two approaches under consideration,” said MTA Spokesman Kevin Ortiz.