M25 motorway and Thurrock off junction 31 (to the east of London). Cobham services opened on 13 September 2012. Originally, the M25 was unlit except for sections around Heathrow, major interchanges and Junctions 23–30. Originally, low pressure sodium (SOX) lighting was the most prominent technology used, but widening projects from the 1990s onwards have all used high-pressure sodium (SON) lighting and this has diminished the original installations. By 2014 only one significant stretch was still SOX-lit (Junction 25–26) and the units were removed the same year. The motorway passes through five counties. Junctions 1A–5 are in Kent, 6–14 are in Surrey, 15–16
M25 motorway table below gives details of each junction, including the roads interchanged and the destinations that are signed from the motorway on the blue advance direction signs. Figures in kilometres are from the driver location signs; figures in miles are derived from them. !scope=col| miles !scope=col| km !scope=col| Clockwise exits (A carriageway) !scope=col| Junction !scope=col| Anti-clockwise exits (B carriageway) !scope=col| European Route Citations Sources M25 motorway The M25 or London Orbital Motorway is long encircling almost all of Greater London, England (with the exception of North Ockendon). An ambitious concept to build four concentric ring roads around London was first mooted