I had a strange and otherwise unlikely thing happen a while back. Coming up to a stop sign I was slowing braking a little hard when my front tire came to rest on one of the standing, egg yoke looking road button markers. As it turns out this one was not attached to the road surface and I slide along sitting on top of it and came to rest in the middle of the busy intersection.
Felt stuppid ending where i did as everyone sat looking at me but no collision.

Gary