Large ramp on grid map is not flush with the ground

I found a small issue on gridmap.

The large ramp beside the tube structure on grid map isn't fully flush with the ground, sometimes causing the rear most chassis nodes of long vehicles with a long rear overhang, like the city bus, to get caught in it.




Hitting the ramp with the Hero bus at over 140kph seems to cause the rear end to get caught on the ledge pretty much every time.