South Cross Route to Parkway D Radial
This motorway, as its snappy title implies, never got very far into the planning process. It was one of the parts of the Ringway plan that was scheduled in so late as to be barely worth considering in the 1960s beyond pencilling in a line on the map. As a result, very little is known about the road, except that something was planned roughly along this alignment, and that it was due to be constructed very late in the programme. One document suggests that it would be "post-1991" - but then again, this was also the time frame given for the North and South Cross Route, so the long wait before construction isn't an indication that it was considered less important than other plans.
It is also known that it is descended from one of Abercrombie's proposals, which was known as Parkway E. Plenty of documents and internal memos show that GLC planners disliked the use of Abercrombie's terminology and, despite copying most of his ideas, were incredibly keen to change all the names. This one, confusingly, had the name 'Parkway E' replaced with a clunky title that still incorporates another Abercrombie term, 'Parkway D', which referred to part of what became Ringway 3.
As is always the case with a road that failed to get very far towards construction, tracking down the fine details of the SCRPDR's route is not easy. For a long time, a small number of plans, much too small to give the route accurately, were all we had. Then it turned up in the most unlikely of places: a consultants' report about the M23, published in the early 1960s, whose maps just happened to drift far enough east to show this motorway too.
It would begin on the Ringway 1 South Cross Route at Loughborough Junction, east of Brixton (right). It was to follow the railway line south from here, parallel to the B222 Milkwood Road through Herne Hill, and then continue to run along the edge of Brockwell Park close to the A215 to reach West Dulwich. The major railway junction just south of the A205 South Circular Road was to be the site of the SCRPDR's interchange with the Balham Loop motorway, dropped from the plans in 1967.
From here, it would turn to follow the line south-west, across the top edge of Norwood Park and through Crystal Palace, still always alongside the railway. At South Norwood, just beyond the A213 Penge Road, the motorway would join the line of Ringway 2's Southern Section briefly, with the two running in a double-deck arrangement through a complex junction (shown left; click to enlarge). At one point the motorway routes would have crossed another railway line, with Ringway 2 passing below it and the SCRPDR above.
After leaving the line of Ringway 2, the motorway would make a new line through open land, passing through Aylesford Avenue to reach Crouch Oak Wood. From here it would turn to face south, running along the eastern edge of Bethlem Royal Hospital and over the A232 Wickham Road, into a corridor of land (still vacant today) on the border between Bromley and Croydon Boroughs, between Oak Avenue and The Alders. It would emerge at Spring Park on the A2022 Kent Gate Way, where most documents show it terminating at Ringway 3's Southern Section.
The SCRPDR is one of a very small number of entirely new radial routes in the Ringway plan, and at first a motorway from Central London that doesn't even reach open countryside seems like rather a strange idea. But then, considering the apalling state of South London's road network, perhaps GLC planners realised they didn't just need new routes for traffic heading outside London, they needed a whole new motorway just for traffic trying to get to the suburbs. It was a good enough idea to have been proposed right back in 1944.
In actual fact, the SCRPDR is described in one or two early documents as the 'Hastings Radial' (shown right), but either the extension outwards to the A21 was uncertain or it had been cancelled by the late 1960s because these references stop before too long. Instead, the most common situation is that the SCRPDR line terminates at Addington, just south-east of Croydon.
The thought that it might stop dead at Addington is intriguing, because seemingly all commercial maps and road atlases that show a "proposed" line for Ringway 3's Southern Section will only show it between Addington (the southern terminus of SCRPDR) and the Dartford Tunnel (such as in the map extract below left; click to enlarge). The line west of here is never marked.
The SCRPDR is really quite an enigmatic motorway all round: like the PNLR, no part of it was built, but the SCRPDR got much further along the planning process before being derailed. It was such a key part of the GLC's proposals that, in about 1964, its line was officially protected, preventing any new development on its route. This restriction was lifted in about 1969 after lobbying from Lambeth Council, who argued that, since the motorway was not programmed until the 1990s, it was counterproductive to allow such huge swathes of land to go undeveloped when it could be used for light industrial units, many of which would be life-expired by the time the motorway was supposed to be built anyway. As a result the line is highlighted in several places by a linear development of 'tin shed' commercial buildings, especially running south along the railway line from Loughborough Junction.
Despite it clearly having been planned in detail and protected, references to it are scarce, to the extent that the name South Cross Route to Parkway D Radial only cropped up after about a year of research and Hastings Radial only became clear very recently. For a long time, a line on overview maps was all we had, so it went by the temporary name 'Mystery Southern Motorway'. The MSM does, at least, have the advantage of being shorter and more memorable than the road's real moniker.