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
History of the London Underground early years of the 20th century, UD signs appeared outside stations in central London. World War I delayed extensions of the Bakerloo and Central London Railways, and people used the tube stations as shelters during air raids in 1915. After the war, government-backed financial guarantees were used to expand the network, and the tunnels of the City and South London and Charing Cross, Euston and Hampstead Railways were linked at Euston and Kennington, although the combined service was not named the Northern line until later. The Piccadilly line was extended north to Cockfosters and took over District line branches to