WOODBRIDGE, N.J. (AP) — A sinkhole on a major New Jersey highway has blown tires on 18 vehicles.

The sinkhole was discovered around 6 a.m. Thursday in the right lane of the Garden State Parkway southbound in Woodbridge.

The New Jersey Turnpike Authority oversees the parkway. Turnpike authority spokesman Tom Feeney says engineers are trying to figure out the cause. He says possibilities include failure of a nearby culvert or collapsed drainpipes under the road.

Traffic has backed up as workers make a temporary fix. Feeney says a permanent fix is to be made with work at night and on weekends.