The page is filled with "answers" from famous (mostly historical) personalities.
I.e., Erwin Schrödinger's answer: Chicken? Chicken!? Where's my cat?
Actually (and somewhat to my disappointment I must say), after a quick "google" I discovered that there are tons similar of why did the chicken cross the road websites, like this one:
Colonel Sanders' answer: I missed one?
and this one:
Bill Gates' answer: I have just released the new Chicken Office 2000, which will not only cross roads, but will lay eggs, file your important documents, and balance your checkbook...
The fact that there are so many websites makesthe whole thing seem much less novel - and therefore way less funny. Still, Schroedinger's "answer" to the riddle will probably keep me giggling at random points throughout the day.