This is one of my attempt to script a full fledged AI for Cars.I am pretty close to my goal. Now my cars can overtake one another. However, I am yet to test this with multiple vehicles such as trucks and other cars . Most important thing to note is to don’t use slow zones to slow down in turns. This method is commonly used but there is a drawback i,e You can’t predict the size of the zone which may result in slowing down too much or not slowing down enough . What I recommend is to cast a ray to detect if it’s going too fast . Here is a video of what it would look like..