Crews on Wednesday finished repairing a heat-related condition on the train tracks near Northport, a problem that led the LIRR to replace trains with buses between Port Jefferson and Huntington, the Long Island Rail Road said.
The metal rails near the Northport train station on the Port Jefferson branch were "slightly out of alignment" because the high temperatures had caused the metal to expand, spokesman Aaron Donovan said.
"The rails need to be very precisely calibrated," he said. "There's not a lot of room for being out of the normal, exact geometry. You wouldn't notice it by looking at it with the naked eye. It doesn't rise to that level."
Shortly after midnight, the Long Island Rail Road tweeted that the work was done.
LIRR had tweeted around 9 p.m. that trains would be replaced by buses in both directions between Port Jefferson and Huntington. One eastbound train and one westbound train were canceled, the LIRR tweeted later in the night.