Very cool, is that documented somewhere by any chance?

I've noticed the same, the only time I can ever "keep up" with the green lights on my folding Dahon is on 5th ave, the very down-hill portion from 40th street to about 23rd.

There are some special streets though which are not in sync with the other lights: 42nd, 23rd, 14th (maybe 34th)... so as long as I catch each leg within one green light I consider that successful.