History of the London Underground to determine the cause. Following the incident, a system that stops a train automatically if the driver fails to brake was introduced at dead-ends on the London Underground. The Northern City Line was connected to British Rail tracks at Finsbury Park in the 1970s. The last tube train ran in October 1975, and British Rail services began in 1976. In 1977, the Piccadilly line was extended from Hounslow to Heathrow Airport, and in 1986 a platform serving Terminal 4 opened on a loop line. The Fleet line through central London was first proposed in 1965, taking over the Bakerloo line's
Timeline of the London Underground eventually consolidating under the single ownership of the Underground Electric Railways Company of London (UERL), with lines stretching across London. In 1933, the UK Government amalgamated the UERL and the Metropolitan Railway as a single organisation, named the London Passenger Transport Board. The London Underground has since passed through a series of administrations, expanding further by the construction of new extensions and through the acquisition of existing main line routes, culminating in its current form as part of Transport for London, the capital's current transport administration, controlled by the Greater London Authority. This timeline lists significant dates in the history