Commutes along the 4, 5 and 6 trains are about to get messy next week—here's what to know

If your summer weekend plans include hopping on the 4, 5 or 6 trains below Grand Central—don’t. The MTA is suspending service on all three lines south of Grand Central-42 St for two weekends this month, from Friday at 11:30pm to Monday at 5am the weekends of August 15 to 18 and August 22 to 25.

The disruption is due to concrete replacement work under the switches north of 14th Street, which is all part of a larger infrastructure overhaul to keep the system from falling apart (literally). According to the MTA, the work will help prevent leaks and corrosion and ensure smoother, more reliable rides for the 1.1 million daily Lexington line users. While the tracks are closed, the MTA will also squeeze in additional upgrades, including accessibility improvements, tunnel repairs and work at Borough Hall.

Expect serious service changes. The 4 won’t run between Grand Central and Crown Heights–Utica Avenue or New Lots Avenue, though it will still operate locally up to Grand Central from Woodlawn. The 5 will stop short at East 180th Street, serving only riders heading to or from Eastchester–Dyre Avenue. And the 6? That’s a no-go between Grand Central and Brooklyn Bridge–City Hall, though service will continue locally from Pelham Bay Park to Grand Central.

To soften the blow, the MTA is bringing back weekend W trains for the first time since March, running from 7 am to 7 pm on Saturdays and 10 am to 6 pm on Sundays. The 42nd Street Shuttle will also run continuously, including overnight hours, to help shuttle stranded riders between Grand Central and Times Square. From there, alternate lines like the N, Q, R, 2 and 3 will be your best friends for getting downtown—or getting home.

In Brooklyn, the 2 and 3 trains will pick up some of the slack between Borough Hall and Franklin Av–Medgar Evers College, with the 3 train extending all the way to New Lots Avenue, including late nights when it usually sleeps.

The MTA suggests checking mta.info, the MTA app or signing up for text and email alerts before heading out. Because next weekend, your usual downtown ride is going on a concrete cure-cation.