Down my end of the A316 we have those average speed cameras set at 30mph. Policing what? Cones, more cones, even more cones and… another load of cones. Everybody seems to be taking smaller local roads as they can get there (wherever that is) more quickly. People are annoyed and as soon as the restriction ends and you’re on the M3 it seems nobody drives at less than 90mph. I was doing 70 the other day (maybe just under) and was overtaken as if I were a stationary object. Police? What Police? Cameras were treated as a joke. Floor the accelerator, drive at any speed you want/can, see a camera, slam on the brake, drive under the current limit, floor the accelerator again. Repeat till the end of your journey.
50mph won’t change anything if no Police in patrol cars or on superfast motorcycles are about. We all break the rule, don’t we? Otherwise how would you know if your car can top a tonne?