I'm fairly sure Boston has intentionally staggered lights to ensure that drivers don't get successive greens in some areas. I would also bet good money that the

I'm fairly sure Boston has intentionally staggered lights to ensure that drivers don't get successive greens in some areas. I would also bet good money that the alternative is some kind of horrific gridlock from emptying side streets too slowly. Honestly, I'm amazed urban traffic is as good as it is, since the core problems are usually irreducible. (i.e. more people want to go to a place than fit there.) A quick look at gridlock in cities where traffic signals aren't carefully planned and widely respected shows just how bad things can get. (Suburban traffic is another story, but that mostly seems to be about overbuilt roads with no actual planning at all. My hometown has a couple of intersections that literally don't function - you can get caught at a permanent red light.)