On monday I realised that I can't find a crossing in Braunschweig with a restriction. For example no_left_turn. This leads to wrong routing of course. I tried a restriction on the crossing Georg-Eckert-Straße/Bohlweg in Braunschweig. On Tuesday the new rendering of OpenRouteService will take place and I will see how it works out...

See osm.wiki/index.php/Relation:restriction