I drove from Coniston to Oxford today. It took far too long, mostly because both the M6 and the M40 kept bunching up and slowing down. Often, the cause of delays on the motorway isn't an accident - it's too many cars driving too close together. One driver dabs their brakes, the next one does the same, and the whole stretch of motorway slows down.
I don't consider myself the best driver in the world by any means, but it always shocks me that nobody seems to have heard of the two second rule, nobody obeys speed restrictions posted on the overhead signs (except on the "managed" motorways where these are backed up by speed cameras on every gantry), and people persist in changing lanes into too-small gaps. Often doing the right thing can leave you being tailgated and flashed at and feeling significantly less safe for trying to obey the rules.
I can't help but wonder if a second driving test for those wanting to use motorways would be a good idea - but it would have to be applied retrospectively to be of proper use, which would be rather difficult practically and politically.
Here's another thought - could we have camera enforcement to prevent tailgating?
Of course, an even better idea would be significant police presence on the motorways - I saw one marked patrol car in 300 miles today.