Anonymous wrote: Leashes are not necessarily fool-proof.
Neither are seatbelts. And yet...
OP, your dogs are probably awesome, but I've seen too many people who aren't responsible dog owners in this area. Leash your dog. If not because it's the law, and because it protects you (at least a small amount) from liability, do it because it might help you protect your dog. I've watched several bungled "introductions" between dogs who got too close. Were it not for their respective leashes, separating them would've been impossible. If they stay by your side anyway, the leash will be easy to ignore.