Signs forbidding U-turns are posted next to the openings in the concrete barriers along the Kansas Turnpike.
But the driver of a 2006 Dodge Magnum, apparently trying to make a U-turn, drove into the path of a semi Wednesday night, killing four people inside the car, authorities said.
Another man remained in critical condition Thursday at a Wichita hospital.
The driver of the semi was unharmed.
Dead are Michael Minor, 39, of Sedgwick; Lindsey Shain, 23, of Wichita; Chad Kingsley, 27, of Wichita; and Johnette Grimes, 22, of Wichita, said Kansas Turnpike Authority officials.
Minor was driving the car, according to KTA reports.
Michael Meyer, 27, of Wichita — another passenger in the Dodge — remained in critical condition Thursday at Wesley Medical Center, where he was flown by emergency helicopter.
According to KTA reports:
The Dodge was heading south on the Turnpike about 2.5 miles north of the Oklahoma line when the driver pulled over to the shoulder at 9:20 p.m.
The driver then attempted a U-turn through an opening between the concrete barriers separating north- and southbound traffic.
As he was turning, the car was hit on the driver's side.
The driver of the southbound semi, 34-year-old Miguel Guzman Hernandez of Wichita, did not have time to stop when the Magnum turned in front of him, a dispatcher said.
Two people inside the car were ejected out the back of the Dodge, about 20 feet from where the car came to rest in the center lane.
Two people were pinned inside the wreckage.
Traffic in the southbound lanes had to detour for 6 1/2 hours after the crash, according to the KTA.
Condolences for Minor were posted across several online forums for pit bull breeders, expressing sympathy for his wife and young son.
Funeral arrangements for Kingsley and Grimes are pending through Cornerstone of Wichita.