Interesting. For traffic/congestion reasons, Manila, Philippines had (has?) this on a permanent basis, not just for a special event. Your license was coded so that police could easily see if you were allowed to be on the roads that day (otherwise, it was public transit for you).
Bogotá, Colombia has the same restriction.
It doesn't help traffic at all. People just bought another car.
Mexico City started doing this in the 80s or early 90s. The rich just bought more cars as a solution.