Have you ever driven at 50mph on a motorway, knowing it's only because of EU rules that you're being made to drive like a octogenarian
Remember that the current speed limits were set when cars were dynamically a lot less capable than they are now (says the man who's currently editing the product literature for a leading speed enforcement camera developer...).
I'm all for average speed systems. They've a proven ability to smooth traffic flows and, even though you're driving more slowly, you often get there more quickly.*
That said, I'd issues spot fines of £1,000 or more to lane squatters. They are far more dangerous because of the congestion and frustration that they cause. The technology is there to do it and the public support, too.
*I'd also support an increase in the speed limits. It's not absolute speed that kills. It's inappropriate speed. camera systems can differentiate, and prosecute for, dangerous manoeuvres and tailgating (as noted, I'm writing about them professionally at this very moment).
A problem is the 'safety' lobby... as an industry commentator once commented to me, "Having a relative killed in a road incident is a tragedy but it does not make you an instant expert on road safety. Unfortunately, there's a vociferous element which takes the moral high ground."