A broken finger joint forced closure of two lanes of the upper level eastbound side of the George Washington Bridge Tuesday night, causing damage to about 20 vehicles heading toward New York City but no injuries, authorities said.

Finger joints are interlocking steel joints stripped across the roadway of the bridge at various points, allowing it to expand and contract depending on whether it’s hot or cold, according to Port Authority spokesman Steve Coleman.

“And when one of those breaks, obviously it could stick up and then cause problems until it can be repaired,” Coleman said.

That’s exactly what happened at about 9:30 p.m. Tuesday, he said; a finger joint broke, cars sustained damage, mostly to their tires, when they drove over the broken portion and two lanes had to be closed for emergency repair work, which lasted more than five hours.

“We immediately closed those lanes and made those repairs,” Coleman said. “The repairs were completed at about 2:50 a.m., and there were approximately 20 vehicles that suffered damage.”

There were no injuries or crashes, Colman said, adding, “Everything is back to normal” as of early Wednesday morning.