Today I came across a BBC article
Motorway middle-lane hoggers to face on-the-spot fines. It turns out that the proposed fines are not just about middle-lane hogging but about a number of frequently practiced, and arguably "minor" careless driving offences. Predictably though the reader comments mostly focused on the subject in the title. I was even moved to add my own contribution to the comments; something I rarely do.
I have just found another BBC article:
Who, what, why: What's wrong with middle-lane hogging? which, in talking to a number of experts and pundits, aims to discover why middle-lane hogging is a bad thing. I think the article is generally reasonable but I don't think it managed to uncover all of the issues.