New Yorkers who rely on the 1, 2 and 3 subway lines should brace for major disruptions over the next five weekends.

The changes, which go into effect around 9:30 p.m. Friday, were announced by the transit agency in a news release this week. The release stated that 1 trains will not run south of 14th Street, 2 trains won’t run south of 34th Street and 3 trains will not run at all during each weekend between Friday nights and 5 a.m. on Mondays through Aug. 24.

“As one of the oldest and largest systems in the world, we are constantly upgrading infrastructure to keep New York moving and we appreciate riders’ patience as we perform this necessary upgrade,” NYC Transit President Demetrius Crichlow said.

The MTA plans to run 5 trains into Brooklyn during the outages, something the agency doesn’t typically do on weekends. They’ll make local stops down to Flatbush Avenue-Brooklyn College. Riders affected by the 3 train outage can take the 4 line instead.

Regular weeknight disruptions are also planned for the 1, 2 and 3 trains through Aug. 21, according to the MTA.

Councilmember Christopher Marte of Lower Manhattan said his office found out about the changes on July 2.

“Weekend service changes on the 1, 2 and 3 trains will affect thousands of Lower Manhattan residents, yet our office was only given a three week notice and we did not receive a briefing," Marte wrote in a statement. “Had we been notified earlier, we could have helped spread the word and given our constituents more time to plan. The MTA needs to communicate more consistently with City Council offices when major service changes affect the communities we represent.”

MTA spokesperson Eugene Resnick said the agency notified community boards and elected officials, including Marte, on June 22.

MTA President of Construction and Development Jamie Torres-Springer said the work was necessary to keep the system in a state of good repair.

“ We know people have places to go. But in relative terms, it's when there's a little bit of a dip in terms of ridership, so they're getting the work done,” Torres-Springer said. “ This is a 24/7 system, but it's a 100-year-old system. We got to do work to keep it running.”