Back in the 1960’s the Greater London Council developed a road plan for London called the London Ringway and, had the plan gone ahead, Chessington would have been very different to how we know it today.
The grand plan was to create 4 roads circling London; Ringway 1 circling Central London, Ringway 2 following the route of the North and South Circular, Ringway 4 following today’s M25 to the south and Ringway 3 sat between Ringway 2 and 4.
The planned route for Ringway 3 was through the centre of Chessington intersecting with the A3 and circling round London, East of Heathrow and connecting with the eastern side of today’s M25.
Parts of the Ringways were built and now form parts of the M25 and North Circular but the plan was scrapped in 1973 mostly due to the increasing cost of purchasing land and construction.
For more information on the Ringways see the entry on Wikipedia.
Additionally, see comedian Jay Foreman’s YouTube video on London’s unfinished motorways.