Before Williamsburg and Bushwick are forced to come to terms with a potential years-long suspension of L train service between Brooklyn and Manhattan, the authority has confirmed that it plans to shut down sections of the M train north of Myrtle Avenue for months at a time as soon as summer 2017. The idea, according to the MTA, is to make sure the M is in a state of repair to handle hordes of L train refugees.

"We want to get this work done and make sure the M has no issues of performance when the L work is going on," MTA Chair Tom Prendergast told the Daily News.

Work will be carried out in two stages. Rehab of a metal bridge that runs over a rail yard between the Fresh Pond Road and Middle Village-Metropolitan Avenue stations in Ridgewood will shut down the entire line from Myrtle Avenue to Middle Village-Metropolitan for two months. Once the bridge work is complete, the MTA is planning to demolish and rebuild a century-old concrete viaduct between Myrtle Avenue and Central Avenue.

"The 103 year-old Bushwick viaduct was not built to last forever," said NYC Transit President Ronnie HakimIt in a statement. "It remains safe for subway riders today but severe deterioration of the concrete deck and other components require that it be replaced."

The work will also involve laying new track beds and platforms.

Knickerbocker Avenue and Central Avenue will be without train service for the full (estimated) ten months, and M trains will be rerouted to the J/Z line between Myrtle and Broadway Junction with 25% less frequency during peak hours. L trains will maintain longer peak service to accommodate M riders, and J and Z trains will make all local stops between Marcy Avenue and Broadway Junction.

As for the shuttles, the MTA will run buses from station to station during the first two-month phase, plus an express shuttle from Flushing Avenue to Middle Village, with an in-between stop at the Jefferson L. During phase two, one shuttle will run from Middle Village to Myrtle-Wyckoff, and another from Myrtle-Wyckoff to Myrtle.

The MTA has kept its plans for the L train top secret since news of the impending shutdown leaked in January. Earlier this month, the authority insisted that it wasn't ready to divulge information. The M train shutdowns are expected to impact 60,000 riders, compared to the 300,000 who commute between Brooklyn and Manhattan on the L on an average weekday.

A "community outreach effort" is apparently in the works for impacted neighborhoods, but details are still thin. We'll update as more information becomes available, but in the meantime you might as well head to Bad Old Days to pour one out for your commute. Is it too late to bring back the South 4th Subway Line?

UPDATE: This post has been updated to include additional information from the MTA.

“Both of these structures have deteriorated to the point that there is simply no other option than complete replacement, and undergoing this step will ensure a safe, more reliable experience for customers for decades to come," said HakimIt in a statement. "We will work closely with the affected communities, their elected officials and other representatives to minimize the disruption and address their concerns, and we will do our utmost to complete this work as quickly as possible.”