Track work at a busy Main Line intersection in Mineola means revised schedules this weekend on eight branches, the Long Island Rail Road said.
The Oyster Bay, Huntington/Port Jefferson and Ronkonkoma branches will be most affected, and the commuter service said customers who regularly use those branches should consider South Shore branches as alternatives.
The track work also will cause changes on the Montauk, Babylon, Far Rockaway, Long Beach and West Hempstead branches.
Revised train schedules will be in effect on both Saturday and Sunday.
For the specifics, customers can visit mta.info/lirr or pick up new timetables at any LIRR terminal or branch station.
Customers traveling Saturday and Sunday are urged to allow for plenty of extra travel time if using any of the eight affected branches, according to a news release.
The release said the LIRR will be resurfacing an area of track on the Main Line known as Nassau Interlocking, the junction where the Oyster Bay branch joins the Port Jefferson, Ronkonkoma and Montauk branches.
The work will be done in two phases, the LIRR said.
The first on Saturday requires completely shutting down the Oyster Bay branch with buses replacing trains. It will also result in one of two Main Line tracks being taken out of service, which will affect service on the Port Jefferson, Ronkonkoma, and Montauk trains.
On Sunday, service resumes on the Oyster Bay branch, but the project continues to affect Oyster Bay, Port Jefferson and Ronkonkoma schedules because one Main Line track will be out of service.