It might be the most obviously unfinished motorway in the whole UK, let alone in London. The M23 was supposed to link London with Crawley - but its urban section was a problem that couldn't be solved.
The wait is over! The full map of the Ringways, London’s unbuilt urban motorway network, is now online. Not even the system's planners had anything like this.
A century ago, one short memorandum issued by the Ministry of Transport laid the groundwork for a system of standardised, uniform road signs and a great deal more.