The Port Authority of New York and New Jersey says a piece of metal on the George Washington Bridge popped up in the roadway, flattening tires on about 20 cars.

The finger joint popped up Tuesday night on the inbound upper level of the Hudson River span, closing two lanes of traffic.

The authority said it was caused by wear and tear.

Crews fixed the problem by 2:30 a.m. Wednesday.

The agency said the bridge is inspected frequently and such breakdowns are uncommon.

The joint allows the bridge's roadways to contract and expand in hot and cold weather.

More than 100 million vehicles cross the bridge connecting New York and New Jersey every year.

(Copyright 2012 The Associated Press.)