I got you beat. My street in front of my house is made from big concrete slabs. They are stamped and dated "1953". These aren't crumbling, but they move approx 1" towards the east every year. So after a year or two the cross street (asphalt) starts to buckle, making a mini speed bump.

 

Thanks for the clarification, Ludedude. I guess I should have read the advertisement instead of just the title! So, I actually have mixed feelings about the bumpsteer effect, it's a nuisance but it also adds unexpected thrills!
Tonino.