New York, NY —

If you take the 4 or 5 trains, you may want to leave extra time. The MTA says work on those subway lines will cause delays.

The MTA will be replacing the concrete road beneath the subway tracks south of Grand Central Station. Workers will chip away at it using jackhammers. A temporary track will cover the area under repair and trains passing through will have to travel slowly. The number of subway cars running on the 4 and 5 lines will also be reduced to ease congestion.

Officials say passengers traveling downtown between 86th Street and 14th Street should expect delays of up to 10 minutes. Trains are also expected to be overcrowded especially during the morning and evening rush hours. The work is scheduled to continue through May 22.