Although this is not strictly a GPS, it is useful. My father has an item called a 'traffic master' attached to his dashboard. It is an item that uses electronic waypoints set on motorway bridges to tell you the state of the traffic ahead of you. I don't know if these are available in the US though. I can't find a URL but I seem to remember that these are inexpensive and that the company send you a new one everytime it is upgraded. Hope this is of interest.