The Great North Road may reach from the heart of London all the way to Edinburgh, but it was only ever going to play a walk-on part in London's proposed urban motorway network.
Much of the A1 within Greater London was never destined to be one of the city's urban motorways at all. From its starting point in the shadow of St Paul's Cathedral, the Greater London Council considered the A1 to be a part of its Secondary Road Network until it was almost in the countryside.
South of Barnet, there would be just one major radial motorway serving traffic for the North and the Midlands, and that job belonged to the M1. Branching off the M1 at the never-finished junction 3 would be the Scratchwood Link, a short motorway spur that would have been the effective start of the A1 as a major motorway north, from where the route would join the present line of the A1 at Stirling Corner, near Borehamwood, and then follow the modern-day A1(M) through Hatfield.
The Scratchwood Link would have been less than a mile in length, a positively trivial proposal compared to the grand schemes plotted by the GLC and the Ministry of Transport. But it was never built, and without it, there's an awful lot about the road network in north west London that doesn't make a lot of sense.
Scroll this map to see the whole route
Scroll this map vertically to see the whole route
This description begins at the southern end of the route and travels north.
Scratchwood to Hatfield
The A1's journey as a major high-capacity road, part of the Greater London Council's Primary Road Network and the length of road described on this page, would begin on the M1 at Scratchwood.
Today the M1 doesn't have a junction 3, just a gap between 2 and 4, but the place where junction 3 should have been is easy to spot. The sliproads to London Gateway (formerly Scratchwood) Services form about three quarters of an unfinished motorway junction. It was designed to be the start of the Scratchwood Link, connecting the M1 to the A1.
Striking north-east from the roundabout at Scratchwood, a dual two-lane motorway spur would climb through Mill Hill Golf Course before entering the cut-and-cover Mote Mount Tunnel beneath the woodland at Scratchwood Park. It would turn north, emerging into open air again in the middle of the Stirling Corner Roundabout, today the junction of the A1 and A411. The spur would flow directly into the A1 to the north, with sliproads between the roundabout and the north, but no way for traffic on the roundabout to get to and from the M1.
A junction, as built, would connect to the A5135 Rowley Lane at Borehamwood. A major interchange at South Mimms would then provide connections to the Ringway 3 Northern Section and the A6, in turn linking to the M10 and M1.
From here the road would be a motorway again, the A1(M), travelling north on roughly its present alignment (though the motorway was actually only opened in 1979, some years after the Ringways plans had been abandoned) to reach Hatfield.
An interchange at Roehyde, now A1(M) junction 3, would connect with the Ringway 4 North Orbital Road leading away to the west, and Ringway 4 would then follow the line of the A1(M) through Hatfield. Today the A1(M) traverses the town in a cut-and-cover tunnel, but this section was proposed, in the 1960s, to run at surface level. The A1(M) itself would be a dual four-lane motorway, flanked by two-lane carriageways on either side that would carry local traffic and connect to side roads and private properties.
North of Hatfield, another junction at Stanborough, slightly south of the present A1(M) junction 4, would connect with the Ringway 4 North Orbital Road's continuation east towards Hertford. The A1(M) would continue north, as now, towards Stevenage and Peterborough.
The missing link
The Scratchwood Link was - at first - an integral part of the M1 Hendon Urban Motorway project. The M1's junctions were laid out to relieve the parallel A41 of through traffic, and there were hopes that it could provide similar relief to the A1.
To do that, a junction was built at Page Street (now junction 2) joining the A1 towards London, and a spur would be built at Scratchwood linking to the A1 out of London. Between those points, traffic on the A1 could borrow a length of M1 and bypass the congested road through Mill Hill that, even today, is shared by the A1 and A41.
The distance from the M1 at Scratchwood to the A1 at Stirling Corner is one kilometre, or about two thirds of a mile. But the problem was never the distance - it was the height. The A1 at Stirling Corner sits on a hilltop some 40-50 metres (120-150 ft) higher than the M1 in the valley below. The Scratchwood Link, running directly between the two, would have to find a way to get up there, at a gradient suitable for motorway traffic.
In 1961, the design called for a free-flowing junction, with access to the M1 to and from the south only. The Link would travel up to the top of the hill on two enormous viaducts, both reaching a maximum height of 18 metres (60 ft) above ground level. The southbound one was to be almost a third of a mile in length; the northbound one - which had to also cross the M1 at an angle - would be even longer, almost two thirds of a mile. Engineers described it having "very large skews and considerable spans".
The size and prominence of the twin structures deserved a name, planners decided. They would be called the Mote Mount Viaduct. Fifteen spans of each viaduct would carry them over Mill Hill Golf Course, though how exactly the course could continue to exist beneath a pair of road bridges was not explained. Presumably it wouldn't.
In early 1964, the design of the Link changed completely. In part this was driven by a need to make it cheaper. To do that, and to provide access to the M1 in both directions for a maintenance compound, the interchange was redesigned to a conventional twin-bridge roundabout junction, and the Scratchwood Link would climb the hill more gently on an earth embankment before ducking into a cut-and-cover tunnel near the A1. The tunnel would carry it under the Stirling Corner roundabout, allowing the link to free-flow into the A1 to the north.
The tunnel itself was still too expensive for the Ministry's accountants, who preferred the idea of a cutting. In the end the cost appears to have decided it. In 1965, the M1 construction contract was let, and the Scratchwood Link wasn't in it.
Instead, the bridges for its interchange were installed to serve the maintenance compound, and Scratchwood Services were opportunistically sited there to make use of them. Construction of the actual Link was deferred to a future date when traffic levels required it.
It was noted in 1967 that the reason only three quarters of the roundabout was built - and not the northern quadrant, without which access to and from the services is rather awkward - was thanks to uncertainty over the GLC's proposed line for Ringway 3's Western Section. That route would pass either through or just to the north of the junction, and replace the Scratchwood Link. Until designs for its connection to the junction were known, and the GLC route was either selected or ruled out, no additional work would be done.
In the end, of course, no additional work was ever done, and the Scratchwood Link was never built. As a result, the M1 cannot serve as a bypass for the A1 through Mill Hill, and the A1 degenerates into a congested suburban road as it enters London rather than offering an onward connection to a radial motorway. The Link was re-proposed on a number of occasions, but has not resurfaced since its cancellation in about 1993, and will not now be built. Access to the services remains awkward.
Interestingly, though, if it ever were to be finished, the paperwork is done. The legal orders for the M1, drawn up in 1961, were made in the full expectation that the Scratchwood Link would be built. Even today the road is, in law, a motorway - even if it isn't, in real life, there.
- Route map contains OS data © Crown copyright and database rights (2017) used under the terms of the Open Government Licence.
- Photograph of bridges at Scratchwood is extracted from "Hendon Urban Motorway: Southern Extension of the M1", Ministry of Transport, Crown Copyright 1967; scans kindly provided by Mike Ashworth.
- Photograph of A1(M) Hatfield Tunnel taken from an original by Alpin Stewart and used under this Creative Commons licence.
- Plans of Scratchwood Link from 1961 and 1964 extracted from MT 109/443.
- Photograph of A1 at Mill Hill Circus taken from an original by Martin Addison and used under this Creative Commons licence.
- A1 City-Barnet part of Secondary Road Network: Document Supply WQ3/9904.
- Route, M1-Stirling Corner; north side of roundabout missing due to uncertainty over GLC line for R3W; legal orders for Scratchwood Link; decision to defer Scratchwood Link until traffic levels required it: MT 109/443.
- Route, Stirling Corner-Hatfield: HLG 159/479; MT 120/252; MT 106/398.
- Route through Hatfield: MT 120/248.
- Sections of route to be classified as motorway: MT 120/252.
- Original design with twin viaducts; name of viaduct: MT 118/72.
- Change to tunneled layout with two-bridge roundabout; concerns about cost of link: MT 95/832.