I believe a tourist once managed that on the M25. Apparently the idea of a looping motorway can be a bit beyond some.
While London traffic can be frustrating, it's not actually that bad. At least compared to a lot of American cities, let alone somewhere like Mexico city.
When I went there I discovered that Mario Kart was a documentary. I have never been carsick until I flew South America to rome, then got into a shuttle to my hotel.
To be fair, smaller cities only have them because they never invested in public transportation. Stockholm doesn't have a complete ring yet, and probably never will.
Saw an old episode of Top Gear where they raced from one side of London to the other. 1 user by car, 1 bike, 1 public transit, and finally a boat. Bicycle arrived first, then the boat, 3rd the public transit and lastly the car. That's a bit telling haha