Traffic on Route 8 at the Clearview Mart in Center Township was slowed for a rear-end collision Friday morning that left one driver injured. State police are investigating the crash, which occurred around 11 a.m., but a report was not immediately available. Emergency crews said it appeared the crash occurred when a Butler Ambulance Service van struck the back of a sport utility vehicle in the southbound lane. There were no passengers in the van. The driver, a woman, was taken to Butler Memorial Hospital with apparent minor injuries. The driver and passenger in the SUV, which had a Virginia license plate, were not injured. Both vehicles had to be towed.