Thousands of Long Island Rail Road commuters will be delayed this weekend due to a construction project on a dilapidated bridge.

The project involves demolition of the crumbling 74-year-old Ellison Avenue Bridge.

LIRR officials say that the demolition will affect 40,000 commuters on Saturday and Sunday. They are urging riders to add an extra hour to their commuting time.

For those who are still planning to ride the rails this weekend, buses will be provided on the main line between the Hicksville and Mineola stations. There will also be buses for people at the Carle Place and Westbury stations.

On the Ronkonkoma branch after 7 a.m., all trains will be diverted to the South Shore with buses provided for people who get on at the Bethpage station. There will be no service to Woodside.

Mets fans are urged to use Port Washington branch trains.

For all other branches, close to normal service is expected.

The LIRR has pledged to have the work finished before the Monday morning rush.