New York City commuters faced ongoing disruptions on Tuesday as subway lines experienced suspensions and delays, just a day after MTA chief Janno Lieber reassured the public that the transit system was operational and reliable.

On Tuesday morning, the entire C line was out of service, compelling travelers from Washington Heights in Manhattan to East New York, Brooklyn, to crowd onto the already congested A trains.

Other lines struggled to maintain schedules during rush hour. The No. 1, 2, 5, and 7 trains experienced delays, while the F, M, L, and N lines also ran behind schedule. The MTA reported that express services on the No. 3, A, and D lines were suspended, and the J train was operating on a reduced timetable.

The Staten Island Railway was only partially operational, and several bus routes were rerouted to allow snowplows to clear the streets.

By 1 p.m., the C line remained out of service, and numerous other routes continued to experience delays. The MTA did not provide a comment to The Post regarding the situation.

Adding to the day’s troubles, a smoke-filled subway car on the G line in Queens forced passengers to evacuate. Thankfully, FDNY officials reported no injuries and attributed the incident to an overturned transformer.

Local travel chaos extended beyond the subways, too.

Only six of the Long Island Rail Road’s 11 branches were running Tuesday morning. LIRR officials said in a statement in the afternoon that there would be “regular weekday service for Wednesday morning’s commute with some schedule modifications.”

Dozens of Amtrak cancellations also left hundreds of passengers stranded at Penn Station.

Air travelers fared no better, with thousands of flights in and out of the region’s airports canceled as blizzard-related disruptions dragged on.

-Additional reporting by Reuven Fenton and Nicole Rosenthal