lived in Germany (Mannheim) for a couple of years,
I know Mannheim very well. I think it was a paradigm for numbering the streets and avenues in NY. Mannheim, founded in the time of Baroque era - a time of contradictions but where the rationality was in flower too (Pascal, Leibniz, Newton) - is built grid-like. The origin is the Palace and the Breite Straße (Broad Way) running from the Palace quite through the City. If you look from the Palace to the City the squares on the left
side are numbered from A to K, the squares on the right
side from L to U. Then they are numbered referring to their distance from the Breite Straße from 1 to 7 (or 15), f.e. A1, A2, A3, and so on, altogether 144 squares. The house numbers of each square start at the corner facing the Palace and then are running counterclockwise on the left
side (A to K), and clockwise on the right
side (L to U).
The idea was as follows: The Palace was seen as a fountain whose spout shoots up the Breite Straße and then squares are the water falling down. Therefore the sense of rotation on the left
side was counterclockwise and on the left
side clockwise.
In 1968 my wife lived in C2-1. There are no other street names in the City as these numbers.
Beg your pardon for this excursion.
Best regards