Used all over the world, these simple concrete islands are popular for a reason: they work! They keep traffic moving, preventing traffic jams and idling. They slow traffic to prevent fender-benders at "intersections", and are much more visible than stop signs. Plus there is very little construction and maintenance cost compared to traffic lights. They can be used on 2, 4 or more lanes of traffic, there's nothing the round-about can't do!

Plus they're charming. You can plant the middle with natives to make it look beautiful too.