Where did the M25 come from?

Where did the M25 come from? Chris5156 Thu, 29/10/2026 - 14:28 London’s notorious orbital motorway turns 40 years old today. Where did it come from - and why the number “25”? https://roadsorguk.substack.com/p/where-did-the-m25-come-from?r=63d189&utm_campaign=post&utm_medium=web&showWelcomeOnShare=true