I've had good success with a bull fighting approach. They charge, you step in and turn and kick them in the ribs/head. Repeat until they are no threat.
I can just see myself dodging traffic while dodging and kicking a pit bull. No thanks. I think I'll stick to chemical warfare.
PS. Good luck with a "kick" to the head. I have a friend who is a cop. He said it took three bullets to the head of a pit bull to put him down.