Ofcourse that degree of elevation is way too dangerous!
I was wrong about the radius of those 5 meter hills/elevations, it's far more than 20+ meters, it has too be at least 40 meters otherwise you'll be launched like in the video., but honoustly I don't have a clue but the purpose is to create a flowing blind entry with a heighest level point just before the apex. And indeed it needs to decrease height flowing into the corner with positive camber for maximum grip. Also the steepness of the last part towards the heighest level point determines whether the car or bike will be airborne, like Cadwell park that's a sick jump!
http://m.youtube.com/watch?v=33r-GQ23s2s