Mmmm I know where they are coming from, 50 is such a bore though, 60 would be better.
To be fair its every sensible person that has to suffer with that because of all the nutters doing silly speeds.
Is there a layby you can pause for a sandwich in?
I wonder how long it is before someone works out what time you have to do it in to average 50mph, then gets a stopwatch going. I bet you have to be going some to average 50.