For reasons yet unknown, the driver of a Polish tour bus rammed into a Romanian trailer truck near Feuchtwangen around 2 am in the morning on the A6 motorway.
The 55-year-old bus driver suffered severe injuries, while 23 of his 46 passengers sustained minor injuries.
The 48-year-old driver of the trailer truck was uninjured, police said.
Rescue workers transported people to nearby clinics and were forced to close the autobahn towards Nuremberg for cleanup efforts that took several hours.
Police estimated damages to be around €200,000.