Road scheme and chronology data is courtesy SABRE (where much of it was gathered by member Ross Spur), with additional data from the UK Motorway Archive, the Scottish Roads Archive and the Northern Ireland Roads Site.
The second part of the story, where we learn why exactly the M4 gets narrower on the final approach to Europe’s biggest city.
The M4 into London was one of the UK's earliest and most ambitious motorway projects. It was bold, pioneering... and almost instantly regretted.
An introduction to what I write, and why I write it, and where my strange new road sign simulator fits in to all this.
During the 1960s the UK developed some of the most sophisticated - and strange - electronic variable message signs anywhere in the world. How? And, just as importantly... why?
