The rules for this puzzle are similar to a series by Zzzyxas. There is also a puzzle by KNT with similar rules.
If you are unfamiliar with U-Bahn, here is a guide that covers the core logic.
The first diagram is a standard U-Bahn. Draw a loop network through the centers of some cells, which may branch or turn, but may not have any dead ends. A clue outside the grid indicates how many times the corresponding line shape (i.e. a cross, branch, straight line, or turn) appears in the corresponding row or column, irrespective of the line shape's rotation.
The second diagram is a 6x6 Latin Square. Place the numbers from 1 to 6 exactly once in every row and column. Numbers on arrows must sum to the number in the circle.
The third diagram indicates exactly how many times a cell of the Latin Square contains the given number and the same relative cell of the U-Bahn contains the given line shape.
