The other thing that hasn't been mentioned yet, is the importance of paying attention to the road.
If you're a driver, you don't get to take pictures, look at the flowers, wave at the bears, etc. Your eyes need to be on the road at all times. A lot of times, other drivers will signal if there's something you need to watch out for. It might be that there's a cop, but it might be that a large vehicle is coming through or there's been an accident.
It gets intense and it's ok to pull over if you need to.
Also, if you're arriving via the Dragon, make sure the stuff in your car is secure. You don't want suitcases, coolers, food or pets falling on you.
Have we sufficiently scared all of the first-timers, yet?