1960s plans for the motorway to Stansted and Cambridge kept shifting course, and its brutal extension to Central London never saw the light of day.

The A10 provides a road north from London in what would otherwise be a huge gap between the A1 and M11. But 1960s planners could find no way for it to reach Central London.

Filling a gap in North London's road network, and potentially relieving two of London's existing major roads, this elusive motorway proposal never got beyond the ideas stage.

The Great North Road was only ever going to play a walk-on part in London's proposed urban motorway network.

The main road north from London is missing the connections that would have integrated it with London's planned urban motorways.

The Northern Radials of London's unbuilt urban motorway plan would have smoothed stressful journeys to the capital and bridged gaps in the city's road network.

A fast route through Hertfordshire and Essex, linking provincial towns far from the fringes of London, the North Orbital would have brought new opportunities to Hatfield, Hertford and Harlow but wasn't much of a London orbital.

Its planners did not suspect that this length of orbital motorway would one day be the busiest in the UK. In fact, if there's anything wrong with it, it's that it's a bit too useful.

Rolling through Kent and Surrey, somewhere between leafy London suburbia and the North Downs, the proposed South Orbital Road would carry long-distance traffic between the Channel ports and the west.

The outermost of London's proposed ring roads, Ringway 4 would have run far from the City, avoiding London and linking towns on the fringes of the metropolis.

Ringway 3's western section threaded its way through outer London suburbia. A line was set for this road in the 1940s, but the question of where it would run could seemingly never be settled.

Sweeping through the suburbs from east to west, the southern side of Ringway 3 would have been enormously destructive and intrusive, and yet - oddly - it was never the subject of much protest.

The Eastern Section of Ringway 3 was built and opened in its entirety: we know it as the east side of the M25. The inevitable question is: was that it?

The northern side of Ringway 3 presented few problems - that's why almost all of it exists today, and it was a bit of a struggle to not build the part that's missing.

Of the four rings planned around London, Ringway 3 was the one that almost everybody could agree on. So why was only half of it ever built?

A short connection in London's never-built Ringway network with a surprisingly complicated history and a critical role to play.

A critically important link in London's proposed urban motorway network - but fierce opposition from the locals made the authorities scared to ever reveal its route.

This was the most controversial section of London's planned orbital motorways, and the one over which the most visceral battles were fought between planners and the public.

The east side of Ringway 2, one of London's planned orbital motorways, is a road of two halves: one still discussed today, too important to cancel and yet impossible to build, the other so straightforward that it's been open to traffic for years.

1960s plans to upgrade the North Circular Road to form one of London's motorway "Ringways" would have seen it change out of all recognition.

Ringway 2 was the 1960s plan to replace London's North and South Circular Roads with a new four-lane motorway.

One of the oddest motorway proposals in the London Ringway plans, the Balham Loop appears to be utterly redundant. It was killed off at an incredibly early stage, and little is known beyond its route.

With its busy market, narrow shopping streets and throngs of pedestrians, Camden Town is not an ideal environment for road traffic. With Ringway 1 came a plan to provide this inner London town centre with a bypass.

Desperately-needed but never built, this was one of the only London urban motorway plans that were ever progressed to the construction stage.

The South Cross Route was the most controversial and the most destructive component of Ringway 1, London's planned inner motorway ring, but also the one for which the least information is available.

The strangest part of London's planned inner Motorway Box - not just because it's nothing like the other three sides, but also because it actually got built.

The route and the history of the North Cross Route, proposed in the 1960s as the northern side of London's innermost motorway ring road.

Ringway 1 would have been one of the largest inner ring roads the world had ever seen: an urban motorway encircling about sixty square miles of central London, including the whole of the City, Westminster and all of the present-day Congestion Charging zone, plus almost all of its docklands and the East End.

A guide to some of the terminology and obscure acronyms that sometimes come up in references to London's planned and abandoned motorway network.

A detailed breakdown of all the known cost estimates for proposed Ringways road schemes, taken from evidence at the GLDP inquiry in 1972.