With update 6 out of the way, Maxis has announced update 7 which is currently in development. It'll bring a plethora of traffic fixes. Most notably vehicles will now claim their destination before actually going there, which will prevent flocking. Congestion on busy routes is also handled in a smarter way and vehicles will accelerate and decelerate faster, allowing them to leave buildings and go through intersections more easily, allowing smoother traffic in your city.