Nope. They work. They might not actually be controlling the flow of city traffic, but for the moment you're in the area of one, it's working as it would be expected to.
I know it's 3 years ago and nobody really gives a crap anymore however, they are useful for the player given that they work as they are expected to. Because if you pay attention to them you can see if the traffic is going to change and use it to not run into people
Whenever I get bored, I slow down to the speed that every other car is going and I pay attention to stop lights