Traffic on Interstate 77 in Rock Hill on Sunday came to a dead stop and was backed up for miles after a late-morning wreck damaged a large sign stretching across the highway.
The S.C. Highway Patrol closed northbound and southbound lanes near Exit 83 for six hours as crews worked to fix a digital Amber Alert sign, which authorities said endangered drivers below.
Traffic was rerouted off the interstate, and police prevented vehicles from accessing I-77 at major interchanges, such as Dave Lyle Boulevard, Cherry Road and Celanese Road in Rock Hill.
Lines of cars several miles long snaked around nearby roads as drivers piled off the interstate in search of alternate routes.
According to the Highway Patrol, a 72-year-old man from Ontario, Canada, was driving south in a four-door Lexus when he fell asleep, then swerved and crashed into a pole connected to the sign at Mile Marker 83.
The driver, Charles Thomas, and a passenger, Jean Thomas, 69, were taken to Carolinas Medical Center in Charlotte with injuries, said Trooper Jeff Gaskin of the Highway Patrol.
Authorities reopened both lanes on I-77 around 5 p.m. Sunday.
