NY 440 begins at the New York–New Jersey state line, mid-span on the east-west Outerbridge Crossing over the Arthur Kill in the Charleston neighborhood of Staten Island.

Crossing into the Rossville neighborhood, the expressway enters exit 3 southbound, connecting to Bloomingdale Road, and parallels a section of the Arthur Kill.

Continuing northeast, NY 440 is routed parallel with the eastern side of the former Fresh Kills Landfill, with exit 5 providing access to Arden Avenue.

Bending northward once again, the West Shore crosses over Fresh Kills creek, and passes through a portion of the William T. Davis Wildlife Refuge.

West Shore continues through the Chelsea-Travis neighborhood, accessible at exit 7 through a service road interchange with Victory Boulevard (itself previously designated as NY 439A, until c. 1968).

[5][6] Running along the northern end of Travis, the West Shore Expressway parallels nearby railroad tracks before entering exit 8, a ramp to South Avenue and the Bloomfield neighborhood.

Dr. MLK Jr. enters exit 12, a junction with Forest Avenue (the portion used by the previously designated, until 1968, NY 439), forming a "four corners" of the neighborhoods just mentioned.

Just north of exit 13, NY 440 passes through an electronic toll collection gantry (for traffic crossing from New Jersey over the Bergen Point Reach to enter onto the northside of Staten Island), then slopes onto the abutments of the Bayonne Bridge, condensing to four lanes.

As proposed, it would begin at the Outerbridge Crossing and run along the west shore of Staten Island to meet the Clove Lakes Expressway (I-278) near the Goethals Bridge.

[6] It was never extended past Victory Boulevard as opposition from both local property owners and environmental activists prevented construction of the rest of the highway.

The segment of the West Shore Expressway southwest of Huguenot Avenue was opened c. 1973[15][16] and became part of a realigned NY 440 on July 1, 1977.