Unknown shot at a truck on Autobahn 7 in Hessen, hit the driver in the head and seriously injured.
The 37-year-old man still managed to steer the truck safely to the next parking lot.
He was taken to a hospital.
According to the police and the public prosecutor's office, it is not yet clear what type of weapon was used.
One of the panes had a hole, said a spokeswoman for the public prosecutor's office.
She did not give any further details.
According to the investigation, the strangers were standing near Eichenzell on a bridge that crosses the A7.
Because of the securing of evidence, the autobahn near Fulda was closed in both directions for a good half an hour.
There was no trace of the perpetrators.
Icon: The mirror
svv / dpa