Ringways 1 to 3 were London roads, pursued with fanatical enthusiasm by the GLC and designed to solve London's urban traffic problems. The North and South Orbitals were not. They were trunk road projects of little interest to the GLC, and justified in isolation. They were meant to move traffic around the Home Counties without it having to go anywhere near London. They would also deflect some traffic attempting to bypass London, and in doing so keep the traffic load of Ringway 3 manageable.
All the same, it makes no sense to look at the Ringways in isolation from the North and South Orbitals, and however their planners saw it, if everything had been built it would very obviously have resulted in a network of four concentric rings. For that reason (and because "North and South Orbital Roads" is a very wordy title) we include these roads in our Ringways pages and we use the invented shorthand "Ringway 4" to refer to them.
Thanks to the rural nature of most of this route, and the protection of much of its alignment from as early as the 1930s, a lot of it was built and incorporated into London's eventual orbital motorway, the M25. A lot of this ring exists, but even where it follows the modern road, there's plenty of history to explore.
The following pages describe the ring in a clockwise direction. Unlike the other Ringways, this journey begins in the south east, taking in the South Orbital first, then passing around the west side of London and finishing with the North Orbital. That's because Ringway 4 would have had no eastern side, so a complete circuit isn't possible.
The first part of the journey around Ringway 4 will be quite familiar: the South Orbital is the southern flank of the M25 and the whole of the M26. The western side is less recognisable, differing in places to the M25 that was built a decade or two later.
Finally, the North Orbital Road is something else entirely: a proposal not expected to be required for decades and often not even planned in detail, making a leisurely trip through the towns of Hertfordshire and Essex. Whether it would be built at all was always a little uncertain, but its ghost remains in some smaller road proposals that keep cropping up even today.