|Location Map ( geo)|
|Runnymede Viaduct that the interchange crosses the Thames.|
|Egham, Surrey / Hythe End, Buckinghamshire|
|Buckinghamshire • Middlesex • Surrey|
|National Highways • Surrey|
|M25, A30, A308, B376, B388|
|Junctions related to the A308|
The Runnymede Interchange is at the point the M25 crosses the River Thames (the crossing of the London Orbital on the east side, at Dartford, is on the A282). The A30 Staines bypass also crosses the River Thames here.
The interchange has two parts: the southern gyratory is called Runnymede Junction (formerly Runnymede Roundabout until 2017), while the northern roundabout interchange is unnamed, but forms junction 13 of the M25.
The loop from the southbound A30 to the southern roundabout is known locally as the "Glanty Loop".
The interchange first opened in 1961 when the A30 crossed the Thames on the original interchange. In 1983, a new bridge opened for the anti-clockwise M25 and the A30 slips therefore the original bridge is now used for the Clockwise M25 and eastbound A30. The B376 & B388 also have spurs linking the interchange for local traffic.
Proposals to widen the M25 in 1994 by means of adding C/D roads would have altered the junction. All movements between the north and south roundabouts would be to the east of the M25. The northern roundabout would be widened on its eastern side to accommodate the extra arm. This scheme was abandoned a few years later in favour of conventional widening so no alterations were made to the junction.
In 2017, work began to alter the Runnymede roundabout, in which the section of roundabout at the east end, between the two carriageways of the A308, was removed. This was replaced with a direct "U-turn" loop allowing traffic from the northern roundabout (from the A30 or M25) to travel directly towards Staines, without going round the roundabout. All parts of the junction are traffic light controlled. Works also included re-surfacing, re-alignment and increasing the number of lanes from some roads. The works were completed in mid-2018. Surrey County Council page on the Runnymede Roundabout.
In 2019, the approach to the northern roundabout from the northbound A30 was widened to five lanes, and the roundabout itself widened and lanes re-aligned. Highways Agency page on the scheme.
|(M4, M40, M1), Heathrow Airport, Watford|
|(M3, M23, M20), Southampton, Gatwick Airport, Dartford|
|London (W), Hounslow, Staines, Kingston upon Thames (A308)|
|Basingstoke, Camberley, Royal Holloway University of London, Savill Garden, Sunningdale, Bagshot|
|Windsor, Runnymede Memorials, Legoland|
|Egham Town Centre, Shopping Centre, Parking 500 spaces||no road number shown|