Source: https://de.wikipedia.org/wiki/Unterfahrschutz_(Nutzfahrzeug)... (in German)
https://www.federalregister.gov/documents/2004/11/05/04-2473...
...and then updated two years later.
Still watered down to the point of near uselessness in order to placate the trucking industry lobbyists.
There's probably an "official" name in some dusty Ministry of Transport document like "side protection collision bar" or some such, and TÜV probably calls it something like "Seitenaufprallschutzgerätüberlaufschutzausrüstung" or some damn thing.
Hinterer Unterfahrschutz
https://www.trucknews.com/features/are-standards-for-trailer...
https://www.iihs.org/news/detail/iihs-recognizes-semitrailer...
Maybe it was just my perception, but I remember driving in Germany (long time ago) and noting how trucks seemed to be driving at a reasonable speed over in the right lane.
Very different from highways in the US where trucks typically drive as if they were just another sedan on the road.