London's missing motorway box

Trouble with the Hammersmith flyover - currently closed for repairs after what look like pretty major defects were found in the structure - makes one ponder on London's major motorway infrastructure, or rather the lack of it.  Paris got its Peripherique in the 1960s.  Equivalent plans for London were drawn up at that time, but only small parts of a proposed inner motorway box were ever implemented, such as the West Cross Route spur road next to Westfield in West London, and the East Cross Route at Hackney Wick.  These, together with the Hammersmith flyover and the elevated part of the A40, are among the few big-scale postwar road structures that were built close to the city centre.

It's not hard, looking at a map of London, to join the dots between the bits that were built and work out where to put most of London's peripherique, but there are a few places where there's no obvious way through.  You can draw your own route and check your work on a rather wonderful website for road enthusiasts, www.cbrd.co.uk, which tells the story and provides a link to a map, overlaid on Google maps, showing in some detail where all the roads would have gone.  Camden Lock, for example, would have benefitted from an east-west flyover with a massive and complex grade separated junction, just north of the canal, much more substantial than anything built at Hammersmith.

It's hard to imagine anything on this scale coming forward today in London - and interesting to speculate on how people would react if it turns out to be necessary to rebuild the Hammersmith flyover from scratch.   Roadbuilding is even more disruptive than railway building, and even rail lines bring the out the nimbies in force, and we have seen this week with the reactions to the HS2 proposals.  But if you lived in Hammersmith, would you rather have a replacement flyover, which would probably turn out to be bigger than the one that is there now, or a lot more traffic through your town centre?  It may be a good time to invest in tunnelling companies.

Finding oneself stuck in traffic on the London road network that we ended up with instead of the motorway box - say on Warwick Road - with several lanes of one way traffic directed through a residential street network that in places is pretty much as built in the nineteenth century - leads one to wonder whether London or Paris came out better off from the 1960s roadbuilding boom.  The two systems, of course, are near perfect mirrors of their respective countries: Cartesian rigour and Napoleonic dirigisme vs. English compromise and muddling through - or do I mean pragmatism?