Saturday marked the first day of the 6-month-long Bay Ridge R station shutdown.

The shutdown is part of a $72 million renovation of three stations along Fourth Avenue, including 53rd Street and Prospect Avenue.

The MTA plans to install brighter lights, electronic display screens and other modern upgrades.

During the 6-month closure, the MTA is rerouting straphangers to nearby subway stops and bus routes.

The renovation is the second of eight stations in Brooklyn to be modernized under the MTA's Enhanced Station Initiative.

The MTA says it opted for a full closure instead of night or weekend construction to get the work done faster.