Just to experiment I put my cruise control on 40 on the way to work earlier this week. I was going on a low traffic curving city street with a 35mph speed limit that had a slight uphill section followed by downhill. No issue on the uphill but on the way downhill I was rapidly approaching 50 MPH so I went to the brake. I don't normally think of cruise as something for hilly areas where I'm going to be engaged in the driving experience Freeway driving on a relatively flat stretch of road without too much traffic is a great place for cruise control.....and I found it worked just fine in this scenario, although it did also do well going up a hill. Look forward to DD's report.