This page is about abandoned proposals to incorporate the A10 into an urban motorway network for London, and not about the A10 in general.
Reaching north into Hertfordshire, the A10 provides a radial route in what would otherwise be a huge gap between the A1 and M11. But there was no way for it to reach Central London.
Today, London has several major roads north: the M1 to the Midlands and the North; the A1 to the East Midlands and Lincolnshire; the M11 to Cambridge and East Anglia. But the A10 has only really been absent from that list since the M11 was completed in the early 1980s.
Until then, the A10 and A11 were of roughly equal significance, and if you were travelling to Cambridge, the A10 was the route you'd probably take. That's why the lengthy improvement to the A10 built between the wars, from London to north of Cheshunt, is the Great Cambridge Road.
One reason the A10 is, today, not one of the major roads north from London is that the Greater London Council's planners couldn't find a way to widen or realign it. Another might be that the M11 stole its thunder.
Passing through a swathe of densely-populated Victorian suburbia, the A10 from the City to Edmonton is one long High Street. It couldn't be widened on-line, and the old London County Council idea to replace it with a purpose-built parallel motorway was, on closer inspection, totally unfeasible. By the late 1960s, when the Greater London Development Plan was being drawn up, the GLC had abandoned hope of improving it.
All of the A10 that remained in the GLC's Primary Road Network, and all that still interested the Ministry beyond London's borders, was the road in outer London, reaching from the Ringway 2 North Circular at Edmonton north to rural Hertfordshire. It's more or less the high-speed section of the A10 as it exists today, a length that's clearly useful, but not by any means one of London's major roads north.
Scroll this map to see the whole route
Scroll this map vertically to see the whole route
This description starts at the southern end of the route and travels north.
Edmonton to Ware
The whole of this route can be travelled today, but if the intentions of the GLC's planners had been realised it would have been an even faster road than it is now.
The route would begin on the Ringway 2 North Circular Road at Great Cambridge Junction. South of this point, the A10 continues in towards Central London, but would not have formed part of the Primary Road Network. The start of the A10 as a major radial route is, therefore, here in Edmonton.
The junction itself would be a grade-separated roundabout interchange, similar to the one built in the 1980s that exists today, but with the North Circular passing over the top rather than underneath.
Striking northwards towards Enfield, the road today is a relatively speedy dual carriageway with multiple signalised junctions. Upgraded to form part of London's major road network, the A10 would have travelled all the way to Ringway 3, the modern-day M25, with just one intermediate junction, a grade-separated interchange at the A110 Southbury Road.
The present-day interchange with the M25 was built as planned, connecting the A10 to Ringway 3's Northern Section, though the motorway ring would have been numbered M16. There were then plans to replace the existing signalised junctions through Cheshunt with another grade-separated junction, segregating all cross-traffic and property accesses from the A10.
At Turnford Interchange, the A10 branches off its historic line to form the Hoddesdon-Ware Bypass, opened in 1974. This is built as planned in the Ringway era, a fast two-lane rural dual carriageway with large grade-separated interchanges and space for a third lane to be added later if required. Its next junction would be Hoddesdon Interchange, today leading only to the A1170 Dinant Link Road, but intended to form the junction of the A10 and the Ringway 4 North Orbital Road. The junction is laid out to allow for an eventual three-level stacked roundabout interchange with Ringway 4 continuing to the west.
From Hoddesdon, the A10 would continue north, as it does today, towards Hertford and Royston.
The lost radial route
The A10 from Central London to the suburbs has been puzzling highway engineers for a century now. Between the wars, the Arterial Road Programme created many modern roads around and into London, but its Great Cambridge Road (now part of the A10) stopped in Tottenham on The Roundway, south of which no suitable line for a new road could be found.
The road still ends there today. Traffic is shunted off along a series of residential streets and around mini-roundabouts to get back to Tottenham High Road, the old line of the A10 away to the east.
At the beginning of the 1960s, as the London County Council began to sketch ideas for an urban motorway network, they tried to find routes for radial motorways to complement the tentative London Motorway Box. In North East London, there were three proposals in close proximity.
Travelling almost east from the Box through Leytonstone was the Eastern Avenue Extension, a proposal that would eventually be built in the 1990s as the A12. Branching off it near Hackney Wick and up the Lea Valley was the Norwich Radial, an early draft of the M11. And then, less than two miles west of the Norwich Radial, and running parallel, was the Cambridge Radial.
This route was clearly a motorway to relieve the A10. In 1963, it started at what was then proposed as the north-eastern corner of the Box, virtually in Hackney town centre, and travelled north along the side of the railway viaduct past Hackney Downs. At Stoke Newington station, it would cross the A10, and the railway line would carry it north close to the A10 all the way to North London.
The forgotten radial route
There doesn't seem to be a single documented reason why the A10 vanished from the plan, its only appearance as a Primary Road being to enter London from the north and finish on Ringway 2, far from Central London and far from any other Primary Road that might continue the journey inwards.
One factor was evidently the difficulty of finding a suitable corridor for construction. Certainly the Ministry and the GLC weren't afraid to propose the bulldozing of buildings to make way for new roads, and a route alongside a railway seemed to be good enough for many routes. But the suburbs of North London are continuous and notably dense, and the buildings alongside the railway through Stoke Newington weren't awaiting redevelopment.
Perhaps more significant was the construction of the M11. It would be a motorway to Cambridge, so longer distance traffic heading in that direction would no longer need the A10. In fact, with the M11 in place, who in future would use the A10 to get from London to anywhere beyond Hertford? The Great Cambridge Road wasn't the road to Cambridge any more, so perhaps it didn't need to be all that Great.
The Possible North London Radial, dreamed up by the GLC's engineers in the early 1960s, was notable for having links to the A10, funnelling traffic into the PNLR for the final leg of its trip to Central London. One purpose of that route, then, might have been to solve the problem of the A10. But it too came to nothing.
Without it, and without the Cambridge Radial, we can only assume that no need was seen for a major radial route in central North London. The A10 would have been - rather as it is today - an important regional approach to London, but not one of national significance, and its upgrade to form part of the Primary Road Network would carry it only to the suburbs. And that, perhaps, would suffice.
- Route map contains OS data © Crown copyright and database rights (2017) used under the terms of the Open Government Licence.
- Photograph of A10 Dalston High Road taken from an original by Dr Neil Clifton and used under this Creative Commons licence.
- Photographs of footbridge over A10 and The Roundway are used under licence from London Metropolitan Archives, City of London (Collage record numbers 236803 and 275162).
- Plan of LCC proposal for the Cambridge Radial is extracted from MT 106/195.
- 1969 plan showing A10 north of Ringway 2 is extracted from Document Supply Wq3/9904.
- Route, R2-R3; A10 only part of PRN R2-R3 by 1965: GLC/TD/C/P/02; Document Supply Wq3/9904.
- R2/A10 interchange: MT 106/393.
- Arterial Road Programme unable to take A10 further into London: route selection and terminus in Tottenham explained in speech by Col. RC Hellard recorded at HLG 46/74.
- LCC proposal for Cambridge Radial motorway: MT 106/195.