I don't think it's a matter of being overly-aggessive. They won't ticket you for going ten over the limit, so why wouldn't you? I think slow drivers are sometimes just as dangerous....they're not keeping up with the traffic flow, and often panic.
Then there's those old people drivers that are just on another level altogether. Ugh. If they can't see over the steering wheel and they can't do the speed limit, take their licenses away. There's lots of lovely seats on public transit or in cabs.
