niekto to tam vysvetluje v komentoch:

This photograph and post is SO very misleading.
1. This intersection is just south of the town of Eichen. The intersection is surrounded by historically wet=drained Agricultural land, containing just a few residences at the edges.
2. All of which are accessible by a *surrounding* road network and Highways.
3. The nearest waterway is a drainage canal named Wehr Bach. The nearest major river is NOT the Rhine, but the Main, located over Eight miles away, which would likely have to flood Frankfurt and Hanau before reaching this community. (The Rhine is 31 miles away)!

To sú oceľové, používajú sa aj v našich končinách. Laicky by som hádal, že tu boli použité najmä pre ich dobrý odpor voči posunutiu a možno aj menší presah do strán, užšie teleso trate a tým aj lepšie odvodňovacie vlastnosti.