The Robert Moses Causeway is an 8.10-mile (13.04 km) state parkway in Suffolk County, New York on Long Island.

[2] The parkway soon takes a slight northeastern turn and later rises to move over Union Boulevard (County Route 50 or CR 50), the Montauk Branch of the Long Island Rail Road, and Orinoco Drive with no access to either roads.

The other ramps exist on a partial cloverleaf just west of Bay Shore Road's interchange with the Southern State.

[2] The first sprawling trestle crossing from West Islip to Captree Island was completed in 1951.

In 1967, a new span was built next to the original bridge, carrying three lanes of northbound traffic.