More optimizations

We are still optimizing performance in the game. While it works fine on most modern equipment, I'd like the game to be accessible on older machines and on mobile phones in particular. The way the road is drawn has been optimized, but night driving scenes still require a lot of compute. The settings of the game's detail from Super, taken down to High, Medium, or Low, help a great deal. Let me know if you have a device that slows down on transitions or esp on night races and what your hardware is.