Originally Posted by grittree
So is there a difference between the red areas and the red/white checkerboard areas? Or is it just like graffiti art, a visual thing for the fans.
The red and white striped bits have mild bumpers, the red is painted track surface. The green is artificial grass that's been glued down. The orange bits at corner apex is severely angled and quite high at peak - no one would intentionally drive over the top of them. They're in the slowest corners as a strong disincentive to cutting it.
At entrance and exit of a corner, the bumpers are a disincentive since they would be destabilizing under braking or power - it is perfectly legal to drive on them though. Mid corner, they are often abused to get a more desirable line, though not always - sometimes it's quicker to round it off.
At exit, the green fake grass is a disincentive since you can't put the power down efficiently on it. If you look at exit, you can see that the green stuff always leads into the red painted area as a safety margin, so if a driver gets unstable on the green stuff, he can catch it on the red pavement. You'll often see a driver go up on the bumpers at exit briefly, then back down onto the track itself. Sometimes they'll over shoot the bumpers all together and sort of straddle the green stuff.
If you look at the red painted area, there's a white line on either side. The inside line is the track boundary, and you can't legally put all 4 over that line. I assume one reason for the red area is it defines a border around the track, and makes video inspection of what a driver did a little easier (like, fully on the red means he had all 4 over the line.