There’s also the other end of the scale, there’s miles of very minor roads, which while they don’t cost the same to maintain as the high profile structures, still have a very low CBR. If they were railways they’d have been closed years ago.
Been driving around Cornwall the last two weeks and our sat-nav seems to delight in taking us down the most minor roads. All of these probably need a twice yearly hedge cutting (if you’ve been on a minor road in Cornwall you’ll know what I mean) even if the tarmac lasts for years. Surely there should be a rolling program of closure of the duplicate routes?
We could, and should, do what the Dutch do and close such duplicate routes to through traffic. Makes the surfacing last longer (because passing motorists' wheels aren't chewing it up) and makes them considerably more suitable for cycling when you're not going to encounter someone hooning around a blind corner following their sat-nav at 60mph.