I JUST FOUND OUT HOW!!! use the street banks and make a spine shape (http://prntscr.com/6v7u3q) and then lower them into the ground so much that you can barely see it. it makes a sidewalk crack noise and you bump a little but you never fall because they are ramps hope i helped!!
If its for sound purposes in a video you can always just add them in the edit. Just layer the sound behind the clips sounds and adjust the EQ as needed.