Deja Vu All Over Again

I was riding on the Belt Parkway Bike Path down near Canarsie when I saw this...




I was vaguely mystified until about 10 feet later I ran over these...



Then I remembered.

Last year during the NYC Century, I saw exactly the same warning in exactly the same place and did exactly the same thing.
You'd think I might have figured it out by now - SLOW BUMPS means -
DON"T RUN OVER THE EXTREMELY SHARP PROTRUSIONS STICKING OUT OF THE ROAD RIGHT IN FRONT OF YOU.