It’s generally thought of as the worst traffic fortnight in Manhattan: the weeks-long proceedings of the United Nations General Assembly, which ensnares all travel patterns on the east side of the island. Road closures, idling black cars, and battalions of cops and Secret Service agents make swaths of Midtown impossible-to-transverse hellscapes for a few days every September. By Tuesday evening, the construction around the JPMorgan supertall that’s taking over a full block on Park Avenue…

