Nowt wrong with the vehicles, it's the codges behind the wheel that have the issues.I think dawdling at 50moh us almost as criminal as smart motorways, almost but not quite.
Driving at 50 means greatly increased lane changes between lanes 1-2 and 2-3. This then causes cars to slam their brakes on and cause tailgating and at worst accidents.
Cars are more than able to do 70 even our kids 20yo 1.2 polo can cruise at 70. Modern motorhomes can do 60 and if they cannot I wonder if they are safe to be on the motorway ....?!
Cheers James