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
London Underground the Underground does not cover most southern parts of Greater London, with less than 10% of the stations located south of the River Thames. The early tube lines, originally owned by several private companies, were brought together under the "" brand in the early 20th century and eventually merged along with the sub-surface lines and bus services in 1933 to form "London Transport" under the control of the London Passenger Transport Board (LPTB). The current operator, London Underground Limited (LUL), is a wholly owned subsidiary of Transport for London (TfL), the statutory corporation responsible for the transport network in Greater