Delaware State Police were called at 11:00 a.m. Friday to the southbound lanes of the highway between Frawley Stadium and the I-295 split.
Four cars and a motorcycle collided.
The driver of the motorcycle, a 51-year-old New Castle man, is being treated for back and leg injuries and is listed in good condition.
Three others were were treated at Christiana Hospital for minor injuries and released.
Troopers are still investigating what led to the crash. No charges have been filed.