On Thu, 19 Oct 1995, John Gladu wrote:

> Something for us slow-pokes to watch out for: the highway laws in Michigan
> prevent semis from using the left lane.  On a two-lane interstate they'll
> blast you for getting in their way in the RIGHT lane.  It took me awhile to
> snap to this and move over into the LEFT lane to allow them to pass me on
> the right.  Enforcing the "no trucks left" must take precedence over the
> "speed limit x".
> 
> Do any other states or locales have this law in effect?

Washington DC beltway - I 495.

Weirder situation was I95 in Northern Virgina had no truck is RIGHT 
lane.  Construction of new lanes was going on and the right lane was the 
former shoulder.  After a guy got killed when his car broke down with no 
shoulder they modified the law to prohibit trucks in that lane.