This app was mentioned in 2 comments, with an average of 4.50 upvotes
Casual game recommendation: Traffic Lanes 2
https://play.google.com/store/apps/details?id=se.shadowtreesoftware.trafficlanes2free&hl=en
I can't put this game down. It's an awesome coordination game where you set up traffic light patterns and switch between them. Traffic gets heavier and drivers get more anxious, and you have to get all of them through. You can assign lights to groups so as to switch between them easily. There are trains, trams, pedestrian crossings, high speed rail, many road setups to choose from (even left-hand drive), and three different modes of play (my favorite is arcade, try to survive without crashing anyone).
If I have one nitpick, it's that the ad that is sometimes is displayed in the bottom can be annoying. I usually play on a tablet with airplane mode on so that is not a problem. Also I've disabled the music, the sound effects alone are pretty good.
On this matter, if someone has any similar games to recommend, I'd be grateful. One other similar game is Traffic Director: https://play.google.com/store/apps/details?id=de.ewintermeyer.td1free&hl=en . Unfortunately the play store is swamped by too many "traffic" games that are really boring, where you simply pass / flip cars through in an interesection. These two games are much better than any of these.