I use mine almost everywhere.
Last night for example, Im riding home at 1am (i work late) and Ive got the cruise set for 52mph.
Car comes up behind me running about 58 or so and then slows down to pace me. 4 lane road, 2 lanes each way and noone but me and him on the road.
So we start down a fairly big hill, i tap my brakes to disengage cruise so I can manually maintain 50ish and this jack head drops back to 40ish. I can barely even see him. Then, in a couple minutes, here it comes again, slowly but surely..rides me for a couple more minutes and then passes me. Gets in front of me and takes the first right hand turn available!!!!!! ARRRRRRRRRRRGGGGGGGGGGGGGGG
These people out there better be glad I do not have a very large truck and a terminal illness!