“I think it’s a 30-minute or less trip for the very few number of people who get to Willets Point right as an L.I.R.R. train is arriving,” Mr. Freemark said.

Riders could also take the No. 7 subway line to the Mets-Willets Point station to catch the AirTrain, though that option could take longer because local trains make many stops.

The Long Island Rail Road could increase train service to the Willets Point station, on the Port Washington line, said Jon Weinstein, a spokesman for the Metropolitan Transportation Authority, the state-controlled agency that oversees the commuter railroad and the subway.

Expansion projects will allow the railroad “to meet growing travel needs and provide more service to key hubs,” including Willets Point and La Guardia, Mr. Weinstein said in a statement.

The authority is building a new train station under Grand Central Terminal and a tunnel connecting it to the Long Island Rail Road, which right now runs to Pennsylvania Station. Costs for the project, which is known as East Side Access and is expected to open in 2022, have ballooned to more than $11 billion. Mr. Cuomo suggested riders could reach the AirTrain using the new route from Grand Central Terminal.

Still, Mr. Cuomo’s focus on the AirTrain proposal has frustrated experts who argue it should not be a top priority when the region’s transit network is in crisis, from the subways to commuter railroads. Kenneth Lipper, a former Port Authority board member appointed by Mr. Cuomo, said the AirTrain was among the “most ill-conceived projects” that he’s experienced in government.

Last week, state lawmakers approved the AirTrain legislation on the final day of the session. The law allows the state to acquire public land along the Grand Central Parkway and the No. 7 line. It appears Mr. Cuomo liked the route because it did not require taking private property.