The man, thought to be 22 and from Scotland, was with two friends when he was hit by a car on the A24 Autobahn in Gudow, near Hamburg, at around 11.40am on Sunday.
In a statement, police in the nearby city of Lubeck said witnesses reported seeing the three men taking “cell phone pictures of themselves”.
The victim was hit by an Audi A6 being driven by a 73-year-old man.
The three men had stayed in Hamburg before travelling to the area by train. Police said they may have been drinking prior to the crash.
The identity of the man has not been released but a Foreign Office spokesman said his family are aware.
The spokesman added: “We are supporting the family of a British man who sadly died in Germany on April 30 and are in contact with the local authorities.”