Or use those lines of little white bumpy spheres.

Can't stand the fact that they put in speed bumps and then don't maintain their paint jobs. I've nailed my head on the car ceiling so many times because I had to slam on the brakes 5m before a pavement-colored speed bump that I suddenly just saw.
Man, I hate it when that happens...

"Most plain girls are virtuous because of the scarcity of opportunity to be otherwise."
-- Maya Angelou