The LIRR is warning commuters to expect delays during the evening rush on four branches due to signal trouble.

“Service on the Ronkonkoma, Port Jefferson and Oyster Bay branches will operate on one of two tracks between New Hyde Park and Mineola,” the 6:23 p.m. advisory from the railroad said.

advertisement | advertise on newsday

And around 7 p.m., the railroad also issued an advisory saying the Babylon branch was experiencing an average of 15-minute delays “due to congestion at Jamaica caused by signal trouble.”

Earlier delays had been brought on by a malfunctioning crossing gate east of the New Hyde Park station, the LIRR said.

At 9:43 p.m. the railroad put out a message saying trains were running “on or close” to schedule.