A new Long Island Rail Road survey shows rider satisfaction numbers plummeting since the launch of Grand Central Madison service.

The poll found overall satisfaction fell to 68% just weeks after the launch of the new service, down from the 80s in months past.

MTA officials said they were not surprised at the drop after the “rough patches” during the start of the service.

Atlantic Terminal-bound passengers saw satisfaction numbers cut in half — from 82% to 41%. But Grand Central Madison passengers actually provided an 80% satisfaction mark.

The MTA announced changes to LIRR service coming Sept. 5 that will increase Penn Station service, as well as direct service to Brooklyn.

Officials said in the morning, more service would be added to Brooklyn from Far Rockaway, Long Beach, Hempstead and Huntington. Also during mornings, trains will continue to run about every eight minutes between Jamaica and Brooklyn, but “more trains will be through trains from Long Island, rather than shuttles.”

But on the Babylon branch, direct service to Brooklyn will end come Sept. 5, a move made by an analysis of ridership.