The Transport Workers Union Local 100 said some MTA buses are out on the road instead of being taken out of service – which is causing concern for both drivers and riders.

TWU said there’s a batch of buses in critical need of repair, what they call a “redline hold.”

“What [the MTA] has been doing is taking them off redline hold; and they’ve been putting them into service, which is a safety concern,” said John Chiarello, president of TWU Local 100.

The union claimed the fleet faces a variety of maintenance issues, including worn-out brake pads.

“Brakes are supposed to be about an inch, and they were being sent out almost to the rivets,” said Chiarello.

The union said Wednesday it’s unclear how many ‘redline buses’ are being used right now, but they claimed it’s happening across the city.

“They’re making decisions that potentially could be dangerous, and we’re going to make sure that doesn’t happen,” said Chiarello.

MTA chair and CEO Janno Lieber addressed the situation on Tuesday in front of city council members. He called the claims “nonsense” and denied that defective or broken buses were service.

“Sometimes our friends in the union make public statements that suggest dangers that are not present in my view,” said Lieber.