A smelly and slippery spill involving human waste caused traffic to back up for miles along Interstate 81 in Cumberland County on Monday. It further snarled traffic in Carlisle and on other nearby road.

The spill occurred before 9 a.m. and caused a motorcyclist to skid out of control and crash in the southbound lanes near the Hanover Street exit in Carlisle.

A Pennsylvania Department of Transportation crew that was doing routine cleanup nearby was called to the scene and determined both southbound lanes needed to be closed, PennDOT spokesman Fritzi Schreffler said.

It took several hours to clean up the spill, which covered both lanes for more than 200 yards, she said. Southbound traffic backed up for miles between Carlisle and the Wertzville Road exit in eastern Cumberland County.

The spill was cleaned up by around noon. However, another accident occurred among the slow-moving vehicles near the intersection of Route 581 and I-81, according to a Pennsylvania State Trooper based at Carlisle. The trooper said no one was seriously injured and the vehicle was off the road, but the crash was further slowing traffic as of around 12:30 p.m.

The trooper said officers were still at the crash scenes and he had no details on the cause of the spill.

PennDOT's Schreffler said she believes the motorcyclist who crashed was able to drive away, and that state police had tracked down the truck that spilled the human waste.

She said the Penn DOT crew had to sweep aside the waste and then wash down the highway.

"All I know is the a truck with human waste lost its load and caused a heck of a slippery situation out there," the state trooper said.