Straphangers on several subway lines faced serious headaches Monday morning.
Signal problems on the Manhattan Bridge snarled service on the northbound B and D trains as well as N, R and F train service, the MTA said.
The signal problems were resolved around noon, however the MTA warned riders to expect extensive delays.
Meanwhile, FDNY activity at Lexington Avenue and 59th Street caused the MTA to suspend N and Q service between Queensoro Plaza and 57th Street-Seventh Avenue for part of the morning.
The FDNY said the activity was related to smoke in a subway tunnel but that it was not a fire.
The smoke condition also impacted R train service.