A Central line train at Lancaster Gate
|Locale||Greater London, Chiltern, Epping Forest, Three Rivers and Watford|
|Transit type||Rapid transit|
|Number of lines||11|
|Number of stations||270 served (260 owned)|
|Daily ridership||3.23 million (approximate)
3.66 million (weekdays) (approximate)
|Began operation||10 January 1863|
|Operator(s)||London Underground Ltd; part of Transport for London (TfL)|
|System length||402 kilometres (250 mi)|
|Track gauge||1,435 mm (4 ft 8 1⁄2 in) standard gauge|
|Electrification||630 V DC Fourth rail|
|Part of a series of articles on|
London Transport portal
The London Underground (otherwise known as the Underground or the Tube) is a metro system serving a large part of Greater London and parts of Buckinghamshire, Hertfordshire and Essex. The system serves 270 stations and has 402 kilometres (250 mi) of track, 45 per cent of which is below ground. Since 2003 LUL has been a wholly owned subsidiary of Transport for London (TfL), the statutory corporation responsible for most aspects of the transport system in Greater London, which is run by a board and a commissioner appointed by the Mayor of London. As of 2012, 91 per cent of operational expenditure is covered by passenger fares.
It incorporates the first underground railway in the world, which opened in 1863 and now forms part of the Circle, Hammersmith & City and Metropolitan lines, and the first line to operate underground electric trains, in 1890, now part of the Northern line. The first tunnels were built just below the surface; later, circular tunnels (tubes) were dug through the London Clay at a deeper level. The Central London Railway was built this way and known as the "twopenny tube" when opened in 1900. The lines were marketed as the UNDERGROUND in the early 20th century on maps and signs at central London stations. The private companies that owned and ran the railways were merged in 1933 to form the London Passenger Transport Board. The Victoria line was opened 1968–71 and the Jubilee line in 1979, and the Jubilee was extended in 1999. The Travelcard was introduced in the mid-1980s and the Oyster card, an electronic ticketing system, in 2003. London Underground celebrated 150 years of operations on 9 January 2013. The system is currently being upgraded to increase capacity.
Today in official publicity, the term 'tube' embraces the whole underground system. The tube map, designed by Harry Beck in 1931, was voted a UK design icon in 2006 and now includes the other TfL railways such as the Docklands Light Railway and London Overground as well as the Emirates Air Line.
The idea of an underground railway linking the City of London with the railway termini in its urban centre was proposed in the 1830s, and the Metropolitan Railway was granted permission to build such a line in 1854. The world's first underground railway, it opened in January 1863 between Paddington and Farringdon using gas-lit wooden carriages hauled by steam locomotives. It was hailed as a success, carrying 38,000 passengers on the opening day, borrowing trains from other railways to supplement the service. The Metropolitan District Railway (commonly known as the District Railway) opened in December 1868 from South Kensington to Westminster as part of a plan for an underground 'inner circle' connecting London's main-line termini. The Metropolitan and District railways completed the Circle line in 1884, built using the cut and cover method where below the surface. Both railways expanded, the District building five branches to the west reaching Ealing, Hounslow, Uxbridge, Richmond and Wimbledon and the Metropolitan eventually extended as far as Verney Junction in Buckinghamshire, more than 50 miles (80 km) from Baker Street and the centre of London. For the first deep-level tube line, the City and South London Railway, two 10 feet 2 inches (3.10 m) diameter circular tunnels were dug between King William Street (close to today's Monument station) and Stockwell, under the roads to avoid the need for agreement with owners of property on the surface. This opened in 1890 with electric locomotives that hauled carriages with small opaque windows, nicknamed padded cells. The Waterloo and City Railway opened in 1898, followed by the Central London Railway in 1900, known as the "twopenny tube". These two ran electric trains in circular tunnels having diameters between 11 feet 8 inches (3.56 m) and 12 feet 2 inches (3.71 m), whereas the Great Northern and City Railway, which opened in 1904, was built to take main line trains from Finsbury Park to a Moorgate terminus in the City and had 16 feet (4.9 m) diameter tunnels.
In the early 20th century the District and Metropolitan railways needed to electrify and a joint committee recommended an AC system, the two companies co-operating because of the shared ownership of the inner circle. The District, needing to raise the finance necessary, found an investor in the American Charles Yerkes who favoured a DC system similar to that in use on the City & South London and Central London railways. The Metropolitan Railway protested about the change of plan, but after arbitration by the Board of Trade the DC system was adopted. Yerkes soon had control of the District Railway and established the Underground Electric Railways Company of London (UERL) in 1902 to complete and operate three tube lines, the Baker Street and Waterloo Railway (Bakerloo), the Charing Cross, Euston and Hampstead Railway (Hampstead) and the Great Northern, Piccadilly and Brompton Railway, (Piccadilly), which all opened between 1906 and 1907. When the 'Bakerloo' was so named in July 1906, The Railway Magazine called it an undignified "gutter title". By 1907 the District and Metropolitan Railways had electrified the underground sections of their lines. A joint marketing agreement between most of the companies in the early years of the 20th century included maps, joint publicity, through ticketing and UNDERGROUND signs outside stations in Central London. The Bakerloo line was extended north to Queen's Park to join a new electric line from Euston to Watford, but World War I delayed construction and trains reached Watford Junction in 1917. During air raids in 1915 people used the tube stations as shelters. An extension of the Central line east to Ealing was also delayed by the war and completed in 1920. After the war government-backed financial guarantees were used to expand the network and the tunnels of the City and South London and Hampstead railways were linked at Euston and Kennington, although the combined service was not named the Northern line until later. The Metropolitan promoted housing estates near the railway with the "Metro-land" brand and nine housing estates were built near stations on the line. Electrification was extended north from Harrow to Rickmansworth, and branches opened from Rickmansworth to Watford in 1925 and from Wembley Park to Stanmore in 1932. The Piccadilly line was extended north to Cockfosters and took over District line branches to Harrow (later Uxbridge) and Hounslow.
London Transport 
In 1933, London's underground railways, tramway and bus operators were merged to form the London Passenger Transport Board, which became known as London Transport, and Harry Beck's diagrammatic tube map appeared for the first time. The outlying lines of the former Metropolitan Railway closed, the Brill Tramway in 1935, and the line from Quainton Road to Verney Junction in 1936. The 1935–40 New Works Programme included the extension of the Central and Northern lines and the Bakerloo line to take over the Metropolitan's Stanmore branch. World War II suspended these plans after the Bakerloo line had reached Stanmore and the Northern line High Barnet and Mill Hill East in 1941. During the war many tube stations were used as air-raid shelters. Following bombing in 1940 passenger services over the West London Line were suspended, leaving Olympia exhibition centre without a railway service until a District line shuttle from Earl's Court began after the war. After work restarted on the Central line extensions in east and west London, these were complete in 1949. After Britain's railways were nationalised in 1948 the reconstruction of the main line railways was given priority over the maintenance of the Underground and most of the unfinished plans of the pre-war New Works Programme were shelved or postponed.
However, the District line need new trains and an unpainted aluminium train entered service in 1953, this becoming the standard for new trains. In the early 1960s the Metropolitan line was electrified as far as Amersham, British Rail providing services for the former Metropolitan line stations between Amersham and Aylesbury. The Victoria line was dug under central London and, unlike the earlier tubes, the tunnels did not follow the roads above. The line opened in 1968–71 with the trains being driven automatically and magnetically encoded tickets collected by automatic gates gave access to the platforms. In 1976 the isolated Northern City Line was taken over by British Rail and linked up with the main line railway at Finsbury Park.
In 1979 another new tube, the Jubilee line, named in honour of Queen Elizabeth's Silver Jubilee, took over the Stanmore branch from the Bakerloo line and was extended through to the Docklands in 1999. Under the control of the Greater London Council, London Transport introduced a system of fare zones for buses and underground trains that cut the average fare in 1981. Fares increased following a legal challenge but the fare zones were retained, and in the mid 1980s the Travelcard and the Capitalcard were introduced. To comply with new safety regulations issued as a result of the King's Cross fire and to combat graffiti a train refurbishment project was launched in July 1991. In 1984 control of London Buses and the London Underground passed to London Regional Transport (LRT), which reported directly to Secretary of State for Transport. One person operation had been planned in 1968, but conflict with the trade unions delayed introduction until the 1980s.
In the early years of the 21st century London Underground was reorganised in a Public-Private Partnership where private infrastructure companies (infracos) upgraded and maintained the railway. In 2003 control passed to Transport for London (TfL) that had been opposed to the arrangement. One infraco went into administration in 2007 and TfL took over the responsibilities, TfL taking over the other in 2010. Electronic ticketing in the form of the contact-less Oyster card was introduced in 2003. The East London line closed in 2007 so that it could be converted into a London Overground line, and in December 2009 the Circle line changed from serving a closed loop around the centre of London to a spiral also serving Hammersmith.
Transport for London 
Transport for London (TfL) was created in 2000 as the integrated body responsible for London's transport system. It replaced London Regional Transport. It assumed control of London Underground Limited in July 2003. TfL is part of the Greater London Authority and is constituted as a statutory corporation regulated under local government finance rules. It has three subsidiaries: London Transport Insurance (Guernsey) Ltd, TfL Trustee Company Ltd and Transport Trading Ltd (TTL), and London Underground Limited is a subsidiary of TTL.
The TfL Board is appointed by the Mayor of London. The Mayor also sets the structure and level of public transport fares in London. However the day-to-day running of the corporation is left to the Commissioner of Transport for London. The current Commissioner is Peter Hendy. The Mayor is responsible for producing an integrated transport strategy for London and for consulting the GLA, TfL, local councils and others on the strategy. The Mayor is also responsible for setting TfL's budget. The GLA is consulted on the Mayor's transport strategy, and inspects and approves the Mayor's budget. It is able to summon the Mayor and senior staff to account for TfL's performance. London TravelWatch, a body appointed by and reporting to the Assembly, deals with complaints about transport in London.
The Underground serves 270 stations. Fourteen Underground stations are outside Greater London, of which five (Amersham, Chalfont & Latimer, Chesham, and Chorleywood on the Metropolitan line, and Epping on the Central line), are beyond the M25 London Orbital motorway. Of the 32 London boroughs, six (Bexley, Bromley, Croydon, Kingston, Lewisham and Sutton) are not served by the Underground network, while Hackney has Old Street and Manor House only just inside its boundaries.
London Underground's eleven lines total 250 miles (402 km) in length, making it the fourth longest metro system in the world, and these are made up of the sub-surface network and the deep-tube lines. The Circle, District, Hammersmith & City, and Metropolitan lines are services that run on the sub-surface network, which has railway tunnels just below the surface and of a similar size to those on British main lines. The Hammersmith & City and Circle lines share stations and most of the track with other lines. The Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria and Waterloo & City lines are deep-level tubes, with smaller trains that run in two circular tunnels (tubes) with a diameter about 11 feet 8 inches (3.56 m). These lines have the exclusive use of a pair of tracks, except for the Piccadilly line that shares track with the District line between Acton Town and Hanger Lane Junction and with the Metropolitan line between Rayners Park and Uxbridge, and the Bakerloo line that shares track with London Overground services north of Queen's Park. Fifty-five per cent of the system runs on the surface, and there are 20 miles (32 km) of cut and cover tunnel and 93 miles (150 km) of tube tunnel. Many of the central London underground stations on deep-level tube lines are higher than the running lines to assist deceleration when arriving and acceleration when departing. Trains generally run on the left hand track, although in some places the tunnels are above each other, for example the Central line east of St Paul's station, or the running tunnels are on the right, for example on the Victoria line between Warren Street and Euston to allow cross-platform interchange with the Northern line between northbound and southbound trains at King's Cross St. Pancras.
The lines are electrified with a four-rail DC system: a conductor rail between the rails is energised at −210 V and a rail outside the running rails at +420 V, giving a potential difference of 630 V. On the sections of line shared with mainline trains, such as the District line from East Putney to Wimbledon and Gunnersbury to Richmond, and the Bakerloo line north of Queen's Park, the centre rail is bonded to the running rails.
Opening dates and stats 
|Current Stock||Future Stock||Trips
per annum (×1000)
per mile (×1000)
|36||C Stock||S Stock from 2013||114,609||4,716|
|60||C Stock and D78 Stock||S Stock from 2013||208,317||5,208|
|Hammersmith & City line[b]||Pink||1864[d]||Sub
|29||C Stock||S Stock (Currently replacing C Stock))||114,609||4,716|
|Metropolitan line||Dark Magenta||1863||Sub
|Piccadilly line||Dark Blue||1906||Deep
|Victoria line||Light Blue||1968||Deep
|Waterloo & City line||Turquoise||1898[f]||Deep
Former main lines now part of LU 
- Bakerloo line - Queen's Park to Harrow & Wealdstone, runs in large part parallel to the LNWR main line (1837), but the actual LU route has always been segregated (especially near Harlesden) and was laid out by the LNWR in 1912-1915.
- Central line - just south of Leyton to just south of Loughton, built by ECR 1856 - same alignment in use by LU today. As no extra tracks were built, this is essentially the oldest railway in use as part of the current LUL system. Also, Loughton to Epping and out to Ongar was built in 1865 by the GER, and again the same alignment is in use by LU today. Connection to main line south of Leyton closed 1970 and lifted 1972. Epping to Ongar was closed 1994 but most of that section east of Epping is in use today as the heritage Epping Ongar Railway.
- Central line - Newbury Park to Woodford junction (west of Roding Valley) via Hainault, built by the GER in 1903, same alignment in use by LU today. Connections to main line south of Newbury Park closed 1947 (in the Ilford direction) and 1956 (in the Seven Kings direction).
- Central line - just north of White City to Ealing Broadway built in 1917 by the GWR, but passenger service only introduced by LU and predecessors since 1920. North Acton to West Ruislip likewise built by GWR on behalf of LU in 1947-8 as parallel line to the pre-existing tracks from Old Oak Common junction towards High Wycombe and beyond, dating from 1904. Presently, the original Old Oak Common junction to South Ruislip route sees only one main line train a day to/from Paddington.
- District line - South of Kensington Olympia, brief sections of the 1862 West London Railway and its 1863 West London Railway Extension used when District extended from Earl's Court in 1872. Later, District had its own bay platform at Olympia built in 1958 along with dedicated track which was actually the 1862/3 WLR/WLER northbound. Southbound WLR/WLRE became the new northbound main line at this time, and a new southbound main line track was built through site of former goods yard. This allowed the 1872 junction to be closed in 1958, while a further connection to the WLR just south of Olympia closed in 1992, so the branch is now totally segregated.
- District line - Campbell Road junction (as was) i.e. near Bromley-by-Bow to Barking - built by the LTSR in 1858, slow tracks built in 1903-1905 (shared with LTSR stopping trains, although District trains were suspended between East Ham and Barking 1905-1908), and finally segregated by 1962, when main line trains ceased serving intermediate stations. LU today using only the 1905 slow tracks.
- District line - westbound track between east of Ravenscourt Park and Turnham Green was built by the LSWR in 1869, as well as Turnham Green to Gunnersbury. Eastbound track between Turnham Green and east of Ravenscourt Park built in 1911, closed 1916 (along with connection to the West London Railway via Hammersmith Grove Road), then re-used to make way for Piccadilly line in 1932 (see below).
- District line - Barking to Upminster - current main line tracks built by LTSR in 1885, but District line only began serving the route in 1902. District then suspended 1905 until the route was quadrupled in 1932 when the service was reintroduced. Main line ceased serving intermediate stations in 1962. LU today only using the 1932 slow tracks.
- District line - East Putney to Wimbledon built by LSWR in 1889 - last regular main line service in 1941 but still sees a few Waterloo services at the start and end of the daily timetable.
- Hammersmith & City - Paddington to Westbourne Park - LU now segregated from the 1854 GWR main line. Originally upon H&C opening in 1864, there were flat junctions in the vicinity of Royal Oak station, but the dive-under east of Westbourne Park was built in 1878.
- Jubilee line - Between Canning Town and Stratford was originally GER twin track built in 1846 (passenger trains in 1847), the current DLR (ex-North London Line) using the original eastern alignment. The Jubilee uses a newer western alignment which was basically the original alignment quadrupled "in stages between 1860 and 1892" for freight services. They were lifted as traffic declined during the 20th century, and re-laid for Jubilee line services commencing in 1999.
- Northern line - East Finchley to Mill Hill East opened 1867 by the GNR, and Finchley Central to High Barnet opened by GNR in 1872, both orginal alignments in use by LU today.
- Piccadilly line - westbound track between east of Ravenscourt Park and Turnham Green built by LSWR in 1869 (originally used for eastbound main line and District services, see above), eastbound track built in 1911 (closed 1916 and then re-used for Piccadilly line in 1932).
All dates above from The London Railway Atlas (Third Edition), by Joe Brown (Ian Allan, 2012).
Main line routes currently sharing track with LUL 
- Bakerloo line - Queen's Park to Harrow & Wealdstone, shared with London Overground Euston to Watford Junction service
- District line - Gunnersbury to Richmond, shared with London Overground North London Line
- Metropolitan line - Harrow-on-the-Hill to Amersham, shared with Chiltern Railways Marylebone to Aylesbury service
London Underground trains come in two sizes, larger sub-surface trains and smaller deep-tube trains. Since the early 1960s all passenger trains have been electric multiple units with sliding doors and a train last ran with a guard in 2000. All lines use fixed length trains with between six and eight cars, except for the Waterloo & City line that uses four cars. New trains are designed for maximum number of standing passengers and for speed of access to the cars and have regenerative braking and public address systems. Since 1999 all new stock has had to comply with accessibility regulations that require such things as access and room for wheelchairs, and the size and location of door controls. All underground trains are required to comply with the The Rail Vehicle Accessibility (Non Interoperable Rail System) Regulations 2010 (RVAR 2010) by 2020.
Stock on sub-surface lines is identified by a letter (such as S Stock, used on the Metropolitan line), while tube stock is identified by the year of intended introduction (for example, 1996 Stock, used on the Jubilee line).
Ventilation and cooling 
When the Bakerloo line opened in 1906 it was advertised with a maximum temperature of 16 °C (60 °F), but over time the tube tunnels have warmed up. In 1938 approval was given for a ventilation improvement programme, and a refrigerating unit was installed in a lift shaft at Tottenham Court Road. More recently, temperatures of 47 °C (117 °F) were reported in the 2006 European heat wave. It was pointed out in 2002 that, if animals were being transported, temperatures on the Tube would break European Commission animal welfare laws. A 2003 study reported that air quality was seventy-three times worse than at street level, with twenty minutes on the Northern line having "the same effect as smoking a cigarette". The main purpose of the London Underground's ventilation fans is to extract hot air from the tunnels, and fans across the network are being refurbished, although complaints of noise from local residents preclude their use at full power at night. In June 2006 a groundwater cooling system was installed at Victoria station. In 2012 air-cooling units were installed on platforms at Green Park station using cool deep groundwater and at Oxford Circus using chiller units at the top of an adjacent building. New air-conditioned trains are being introduced on the sub-surface lines, but space is limited on tube trains for air-conditioning units and these would heat the tunnels even more. The Deep Tube Programme, investigating replacing the trains for the Bakerloo and Piccadilly lines, is looking for trains with better energy conservation and regenerative braking.
Lifts and escalators 
Originally access to the deep-tube platforms was by a lift. Each lift was manned, and at some quiet stations in the 1920s the ticket office was moved into the lift, or it was arranged that the lift could be controlled from the ticket office. The first escalator on the London Underground was installed in 1911 between the District and Piccadilly platforms at Earl's Court and from the following year new deep-level stations were provided with escalators instead of lifts. The escalators had a diagonal shunt at the top landing requiring a sideways step off. In 1921 a recorded voice instructed passengers to stand on the right and signs followed in World War II. It is thought that people stood on the right as it was easier to step off with the right foot at the top of the escalators. The first 'comb' type was installed in 1924 at Clapham Common. In the 1920s and 30s many lifts were replaced by escalators.
There are 426 escalators on the London Underground system and the longest, at 60 metres (200 ft), is at Angel. The shortest, at Stratford, gives a vertical rise of 4.1 metres (13 ft). There are 164 lifts, and numbers have increased in recent years due to a programme to increase accessibility.
Wi-Fi and mobile phone reception 
In the summer of 2012 London Underground, in partnership with Virgin Media, trialled Wi-Fi hot spots in many stations, but not in the tunnels, that allowed passengers free internet access. The free trial proved successful so it was extended to the end of 2012 whereupon it switched to a service, available to subscribers to Virgin Media and others, or as a paid-for service. It is not currently possible to use mobile phones underground and a project to extend the network before the 2012 Olympics was abandoned due to commercial and technical difficulties.
Planned improvements and expansions 
The signalling system on the Northern line is being replaced to increase capacity on the line by 20 per cent by the end of 2014. Capacity can be increased further if the operation of the Charing Cross and Bank branches are separated. New S Stock trains are being introduced on the sub-surface (District, Metropolitan, Hammersmith & City and Circle) lines, and the track, electrical supply and signalling systems are being upgraded in a programme planned to increase peak-hour capacity by the end of 2018. A single control room for the sub-surface network is to be established in Hammersmith and an automatic train control (ATC) system will replace signalling equipment installed from the 1940s. Options for new trains for the Bakerloo and Piccadilly lines are being considered.
Crossrail is under construction and expected to open in 2018, providing a new underground route across central London integrated with the London Underground system. Options are being considered for the route of Crossrail 2 on a north-south alignment across London, with hopes that it could be open by 2033.
Line extensions 
The Croxley Rail Link involves re-routing the Metropolian line's Watford Branch from the current terminus at Watford tube station over the disused Croxley Green branch line to Watford Junction. Funding was agreed in December 2011, and the necessary permission has been requested from the Government. Construction work is expected to start in June 2014 and end by January 2016. It is proposed that the Northern line be extended to Nine Elms and Battersea, and a public enquiry is expected in autumn 2013. It is hoped the stations will open in 2020.
There are suggestions that the Bakerloo Line be extended to Lewisham, and then taking over services on the Hayes Line to relieve capacity on the suburban rail network. The London Borough of Hillingdon has proposed that the Central line be extended from West Ruislip to Uxbridge via Ickenham, claiming the extension would cut traffic on the A40 in the area.
The Underground uses Transport for London's zonal fare system to calculate fares. There are nine zones, zone 1 being the central zone, which includes the loop of the Circle line with a few stations to the south of River Thames. The only London Underground stations in Zones 7 to 9 are on the Metropolitan line beyond Moor Park, outside Greater London. Some stations are in two zones, and the cheapest fare applies. Paper tickets or the contactless Oyster card can be used for travel. Single and return tickets are available in either format, but Travelcards (season tickets) for longer than a day are only available on Oyster cards.
TfL introduced the Oyster card in 2003, this is a pre-payment smartcard with an embedded contactless RFID chip. It can be loaded with Travelcards and used on the Underground, the Overground, buses, trams, the Docklands Light Railway, and National Rail services within London. Fares for single journeys are cheaper than paper tickets and a daily cap limits the total cost in a day to the price of a Day Travelcard. The Oyster card must be 'touched in' at the start and end of a journey, otherwise it is regarded as 'incomplete' and the maximum fare charged. In March 2012 the cost of this in the previous year to travellers was £66.5 million. As of March 2013 contactless payment cards can be used instead of an Oyster card on buses and it is planned to extend this to the Underground in late 2013.
A concessionary fare scheme is operated by London Councils for residents who are disabled or meet certain age criteria. Residents born before 1951 were eligible after their 60th birthday, whereas those born in 1955 will need to wait for they are 66. Called a "Freedom Pass" it allows for free travel on TfL-operated routes at all times and is valid on some National Rail services within London at weekends and after 09:30 on Monday to Fridays. Since 2010, the Freedom Pass has included an embedded holder's photograph; it lasts five years between renewals.
In addition to automatic and staffed ticket gates, the Underground is patrolled by both uniformed and plain-clothes ticket inspectors with hand-held Oyster card readers. Passengers travelling without a valid ticket must pay a penalty fare of £80 (or £40 if paid within 21 days) and can be prosecuted for fare evasion under the Regulation of Railways Act 1889 and Transport for London Byelaws.
Hours of operation 
The tube closes overnight, the first trains running from about 05:00 to just after 01:00 the following morning, with later starting times at weekends. The nightly closures are used for maintenance, but some lines stay open at New Year and close later during major public events such as the 2012 London Olympics. London Underground have proposed extending opening times on some lines at the weekend after 2015, following upgrades to the lines. Some lines are closed for scheduled engineering work at weekends to update the system.
The Underground runs limited service on Christmas Eve with some lines closing early, and does not operate on Christmas Day. Since 2010 a dispute between London Underground and trade unions over holiday pay has resulted in a limited service on Boxing Day.
Accessibility by people with limited mobility was not considered when most of the system was built, and before 1993 fire regulations prohibited wheelchairs on the underground. The stations on the Jubilee Line Extension, opened in 2000, were designed for accessibility, but retrofitting accessibility features to the older stations is a major investment that is planned to take over twenty years. A 2010 London Assembly Report concluded that over ten per cent of the people of London had reduced mobility and with an aging population numbers will increase in the future.
TfL produces a version of the tube map that indicates stations that are step-free from street to platforms. There can also be a step from platform to train as large as 12 inches (300 mm) and a gap between the train and curved platforms, and these distances are marked on the map. Access from platform to train at some stations can be assisted using a boarding ramp operated by staff, and a section has been raised on some platforms to reduce the step.
As of December 2012 there are sixty-six stations with step-free access from platform to train, and there are plans to provide step-free access at another twenty-eight in ten years. By 2016 a third of stations are to have platform humps that reduce the step from platform to train. New trains, such as those being introduced on the sub-surface network, have access and room for wheelchairs, improved audio and visual information systems and accessible door controls.
Delays and overcrowding 
During peak-hours stations can get so crowded they need to be closed. Passengers may not get on the first train and the majority of passengers do not find a seat on their trains, with some trains having more than four passengers every square metre. When asked, passengers report overcrowding as the aspect of the network that they are least satisfied with, and overcrowding has been linked to poor productivity and potential poor heart health. Capacity increases have been overtaken by increased demand, and peak overcrowding has increased by 16 per cent since 2004/5.
Compared with 2003/4, the reliability of the network had increased in 2010/11, with Lost Customer Hours reduced from 54 million to 40 million. Passengers are entitled to a refund if their journey is delayed by 15 minutes or more due to circumstances within the control of TfL, and in 2010, 330,000 passengers of a potential 11 million Tube passengers claimed compensation for delays. A number of mobile phone apps and services have been developed to help passengers claim their refund more efficiently.
London Underground is authorised to operate trains by the Office of Rail Regulation, and the latest Safety Certification and Safety Authorisation is valid until 2017. On 19 March 2013 there had been 310 days since the last major incident, when a passenger had died after falling on the track.
In November 2011 it was reported that 80 people had committed suicide in the previous year on the London Underground, up from 46 in 2000. Most platforms at deep tube stations have pits, often referred to as 'suicide pits', beneath the track. These were constructed in 1926 to aid drainage of water from the platforms, but halve the likelihood of a fatality when a passenger falls or jumps in front of a train.
Design and the arts 
Early maps of the Metropolitan and District railways were city maps with the lines superimposed, and the District published a pocket map in 1897. A Central London Railway route diagram appears on a 1904 postcard and 1905 poster, similar maps appearing in District Railway cars in 1908. In the same year, following a marketing agreement between the operators, a joint central area map that included all the lines was published. A new map was published in 1921 without any background details, but the central area was squashed, requiring smaller letters and arrows. Harry Beck had the idea of expanding this central area, distorting geography, and simplifying the map so that the railways appeared as straight lines with equally spaced stations. He presented his original draft in 1931, and after initial rejection it was first printed in 1933. Today's tube map is an evolution of that original design, and the ideas are used by many metro systems around the world.
Currently the standard tube map shows the Docklands Light Railway, London Overground and Emirates Air Line as well as the London Underground; a more detailed map covering a larger area, published by National Rail and Transport for London, includes London Tramlink and suburban railway services. The tube map came second in a BBC and London Transport Museum poll asking for a favourite UK design icon of the 20th century and the underground's 150th anniversary was celebrated by a Google Doodle on the search engine.
While the first use of a roundel in a London transport context was the trademark of the London General Omnibus Company registered in 1905, it was first used on the Underground in 1908 when the UERL placed a solid red circle behind station nameboards on platforms to highlight the name. The word "UNDERGROUND" was placed in a roundel instead of a station name on posters in 1912 by Charles Sharland and Alfred France, as well as on undated and possibly earlier posters from the same period. Frank Pick thought the solid red disc cumbersome and took a version where the disc became a ring from a 1915 Sharland poster and give it to Edward Johnston to develop, and registered the symbol as a trademark in 1917. The roundel was first printed on a map cover using the Johnston typeface in June 1919, and printed in colour the following October.
After the UERL was absorbed into the London Passenger Transport Board in 1933, it used forms of the roundel for buses, trams and coaches, as well as the Underground. The words "London Transport" were added inside the ring, above and below the bar. The Carr-Edwards report, published in 1938 as possibly the first attempt at a graphics standards manual, introduced stricter guidelines. Between 1948 and 1957 the word "Underground" in the bar was replaced by "London Transport". As of 2013, forms of the roundel, with differing colours for the ring and bar, is used for other TfL services, such as London Buses, Tramlink, London Overground, London River Services and Docklands Light Railway. Crossrail, due to open in 2018, is to be identified with a roundel. The 100th anniversary of the roundel was celebrated in 2008 by TfL commissioning 100 artists to produce works that celebrate the design.
Fifty-nine of the 270 London Underground stations are listed buildings. The Metropolitan Railway's original seven stations were inspired by Italianate designs, with the platforms lit by daylight from above and by gas lights in large glass globes. Early District Railway stations were similar and on both railways the further from central London the station the simpler the construction. The City & South London Railway opened with red-brick buildings, designed by Thomas Phillips Figgis, topped with a lead-covered dome that contained the lift mechanism. The Central London Railway appointed Harry Bell Measures as architect, who designed its pinkish-brown steel-framed buildings with larger entrances.
In the first decade of the 20th century Leslie Green established a house style for the tube stations built by the UERL, which were clad in ox-blood faience blocks. Green pioneered using building design to guide passengers with direction signs on tiled walls, with the stations given a unique identity with patterns on the platform walls. Many of these tile patterns survive, though a significant number of these are now replicas. Harry W. Ford was responsible for the design of at least 17 UERL and District Railway stations, including Barons Court and Embankment, and claimed to have first thought of enlarging the U and D in the UNDERGROUND wordmark. The Met's architect Charles Walter Clark had used a neo-classical design for rebuilding Baker Street and Paddington Praed Street stations before World War I and, although the fashion had changed, continued with Farringdon in 1923. The buildings had metal lettering attached to pale walls. Clark would later design "Chiltern Court", the large, luxurious block of apartments at Baker Street, that opened in 1929. In the 1920s and 1930s, Charles Holden designed a series of modernist and art-deco stations some of which he described as his 'brick boxes with concrete lids'. Holden's design for the Underground's headquarters building at 55 Broadway included avant-garde sculptures by Jacob Epstein, Eric Gill and Henry Moore.
When the Central line was extended east, the stations were simplified Holden proto-Brutalist designs, and a cavernous concourse built at Gants Hill in honour of early Moscow Metro stations. Misha Black was appointed design consultant for the 1960s Victoria line, contributing to the line's uniform look, but each station had an individual tile motif. The stations of the 1990s extension of the Jubilee line were much larger than before and designed by architects such as Norman Foster and Michael Hopkins.
Many platforms have unique interior designs to help passenger identification. The tiling at Baker Street incorporates repetitions of Sherlock Holmes's silhouette and at Tottenham Court Road semi-abstract mosaics by Eduardo Paolozzi feature musical instruments, tape machines and butterflies. Robyn Denny designed the murals on the Northern line platforms at Embankment.
The first posters used a number of type founts, as was contemporary practice, and station signs used sans serif block capitals. The Johnson typeface was developed in upper and lower case in 1916, and a complete set of blocks, marked Johnson Sans, was made by the printers the following year. A bold version of the capitals was developed by Johnson in 1929. The Met changed to a serif letterform for its signs in the 1920s, used on the stations rebuilt by Clark. However, Johnson was adopted systemwide after the formation the LPTB in 1933 and the LT wordmark was applied to locomotives and carriages. Johnson was redesigned, becoming New Johnson, for photo-typesetting in the early 1980s when Elichi Kono designed a range that included Light, Medium and Bold, each with its italic version. The typesetters P22 developed today's electronic version, sometimes called TfL Johnson, in 1997.
Posters and patron of the arts 
Early advertising posters proclaimed the advantages of travelling using various letter forms. Graphic posters first appeared in the 1890s, and it became possible to print colour images economically in the early 20th century. The Central London Railway used colour illustrations in their 1905 poster, and from 1908 the underground group, under Pick's direction, used images of country scenes, shopping and major events on posters to encourage use of the tube. Pick found he was limited by the commercial artists the printers used, and so commissioned work from artists such as Edward McKnight Kauffer, Graham Sutherland, Charles Sharland and the cartoonist George Morrow. The Johnson Sans letter form began appearing on posters from 1917. The Met, strongly independent, used images on timetables and on the cover of its Metro-land guide that promoted the country it served for the walker, visitor and later the house-hunter. By the London Transport was formed in 1933 the UERL was considered a patron of the arts and over 1000 works were commissioned in the 1930s, such as the cartoon images of Charles Burton and Kauffer's later abstract cubist and surrealist images.
Harold Hutchison became London Transport publicity officer in 1947, after World War II and nationalisation, and introduced the "pair poster", where an image on a poster was paired with text on another. Numbers of commissions dropped, to eight a year in the 1950s and just four a year in the 1970s, with images from artists such Harry Stevens and Tom Eckersley. Art on the Underground was introduced in 1986 by Henry Fitzhugh to revive London Transport as a patron of the arts with the Underground commissioning six works a year, judged first on artistic merit. In that year Peter Lee, Celia Lyttleton and a poster by David Booth, Malcolm Fowler and Nancy Fowler were commissioned. Today commissions range from the pocket tube map cover to installations in a station. Similarly, Poems on the Underground has commissioned poetry since 1986 that are displayed in carriages.
In popular culture 
The Underground (including several fictitious stations) has been featured in many movies and television shows, including Skyfall, Die Another Day, Sliding Doors, An American Werewolf in London, Creep, Tube Tales and Neverwhere. The London Underground Film Office received over 200 requests to film in 2000. The Underground has also featured in music such as The Jam's "Down in the Tube Station at Midnight" and in literature such as the graphic novel V for Vendetta. Popular legends about the Underground being haunted persist to this day.
Call of Duty: Modern Warfare 3 has a level named Underground where most of the level takes place between the dockyards and Westminster while the player and a team of SAS attempt to take down cargo being shipped using London Underground. The London Underground map serves as a playing field for the conceptual game of Mornington Crescent (which is named after a station on the Northern Line) and the board game The London Game.
Notable people 
- Charles Pearson (1793–1862) suggested an underground railway in London in 1845 and from 1854 promoted a scheme that eventually became the Metropolitan Railway.
- John Fowler (1817–1898) was the railway engineer that designed the Metropolitan Railway.
- Edward Watkin (1819–1901) was chairman of the Metropolitan Railway from 1872 to 1894.
- James Henry Greathead (1844–1896) was the engineer that dug the Tower Subway using a method using a wrought iron shield patented by Peter W. Barlow, and later used the same tunnelling shield to build the deep-tube London & South London and Central London railways.
- Charles Yerkes (1837–1905) was an American who founded the Underground Electric Railways Company of London (UERL) in 1902, which opened three tube lines and electrified the District Railway.
- Edgar Speyer (1862–1932) Financial backer of Yerkes who served as UERL chairman from 1906 to 1915 during its formative years.
- Albert Stanley (1874–1948) was manager of the UERL from 1907, and became the first chairman of the London Passenger Transport Board (LPTB) in 1933.
- Frank Pick (1878–1941) was UERL publicity officer from 1908, commercial manager from 1912 and joint managing director from 1928. He was chief executive and vice chairman of the LPTB from 1933 to 1940. It was Pick that commissioned Edward Johnson to create the typeface and redesign the roundel, and established the Underground's reputation as patrons of the arts as users of the best in contemporary poster art and architecture.
- Robert Selbie (1868–1930) was manager of the Metropolitan Railway from 1908 until his death, marketing it using the Metro-land brand.
- Edward Johnston (1872–1944) developed the Johnson Sans typeface, still in use today on the London Underground.
- Harry Beck (1902–1974) designed the tube map, named in 2006 as a British design icon.
See also 
- London at Wikipedia books
- List of London Underground stations
- List of the busiest London Underground stations
- Timeline of the London Underground
- Tube Challenge
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