This is a Realism Traffic AI overhaul, which means that it's not just a modification of the game. It has a very different feel than what you're used to in the game.

AI is the most important thing in the game, so this mod makes it more lifelike. The biggest difference is that the traffic is much more realistic, especially on highways. The cars will behave in a real-life way, which means that they'll drive in different lanes, and they'll be able to turn at the traffic lights.