Harrison Ford Kisses Wife Calista Flockhart on New York City Subway Platform

Harrison Ford and his wife Calista Flockhart are still going strong ... because they're packing on the PDA while packing into a commuter train in the Big Apple.

The "Indiana Jones" star trekked out to New York City to see his wife amid rumors of possible trouble in paradise ... and they looked like two lovebirds as they rode the subway.

Harrison and Calista kissed and hugged on the subway platform ... then she caught a train to her Off-Broadway play "Curse of the Starving Class," and he took a separate train to Columbus Circle.

It's pretty rare to see someone as famous as Harrison riding the NYC subway system ... and he even chatted up a fellow straphanger, telling her it had been years since he's taken the train.

Harrison and Calista have been living on separate coasts -- he's in California and she's in NY -- as she performs her play ... but it looks like the distance between them isn't hurting their marriage ... at least based on what we're seeing here.