MADISON, Wis. -

A disabled tractor trailer caused a seven mile backup on Interstate 39/90 in Rock County Friday afternoon, according to the Wisconsin State Patrol.

The incident delayed traffic about 4 hours.

The backups started in the eastbound lanes at mile marker 167 between Newville and Janesville. It was cleared by 5:11 p.m., the State Patrol said.

Motorists were advised to exit at Newville of Highway 73 and take Highway 59 to Edgerton and Highway 51 to Janesville to avoid traffic delays.