M23 Motorway - History

History

The M23 was planned to relieve congestion on the A23 through Streatham, Thornton Heath, Purley and Coulsdon in south London and was originally intended to terminate in Streatham Vale at a junction with the controversial London Ringways Plan's Ringway 2 (the intended replacement of the South Circular Road (A205)).

In an earlier version of the Ringways Plan it would have continued into central London where it would have met the Balham Loop spur from Ringway 1 (the London Motorway Box) at Tooting. This was dropped in 1967 when the northern terminus was changed to Ringway 2.

By 1972 the southern section of Ringway 2 had been dropped from the plan, which meant that had the M23 continued north into inner London it would not have had the motorway required at its northern end to distribute traffic to the east and west. The M23 plan was gradually scaled back further to omit the section across Mitcham Common and end the motorway at an unsuitable location on Croydon Road (A232) before the plan was postponed indefinitely. The proposals were finally dropped in the mid-1980s but much of the land reserved for the route was not released by the Department for Transport until the mid-1990s.

The missing section of motorway and the missing six junctions north of Hooley were not constructed due to difficulties in finding a practical route through Wallington, Beddington and Mitcham to Streatham. Large scale residential demolitions would have been required, and local opposition to the motorway was strong. The scale of the four-tier junction between the M23 and the M25, one of only three stack interchanges in the UK, is indicative of the importance attached to the M23 at that time.

The motorway was constructed between 1972 and 1975, at the same time as the southern section of the M25 from Godstone to Reigate (M25 junctions 6 to 8). The current northern terminus at junction 7 uses the original sliproads to meet the A23 and a flyover above the junction built for the onward northern continuation remains unused.

A new junction (J10A) was opened in 1997, between J10 and J11, for access to the new Crawley neighbourhood of Maidenbower. It was financed as part of the development of Maidenbower by the construction consortium. It gives only off-access southbound and on-access northbound.