As of last week they cancelled the Jitney until April 9th.
Not everyone knows the Jitney - https://en.wikipedia.org/wiki/Hampton_Jitney
People who own homes in both NYC and The Hamptons don’t use the Jitney. Maybe their poorer friends do. That’s for day trippers and weekend guests. The Long Island Railroad goes out there, too. I don’t know how the Hamptons can keep homeowners like Ina and Jeffrey Garten out of their own villa. And given the huge tracts of land people live on, they can self-isolate at their pleasure.