The market for trams became smaller as other tramways were being forced to close at that time, as the 1948 nationalisation of electricity suppliers removed access to cheap electricity for those undertakings which owned their local power company. Alexander Valentine, one of the five full-time members of the London Transport Executive, saw trams as a major cause of road congestion, which would be relieved by the introduction of buses, with the aesthetic benefit of doing away with overhead wires and their noisy operation. A report in The Economist in 1952 suggested a more comprehensive list of reasons for their demise, including: the 1870 Tramways Act, which placed a great financial burden on the operator for road maintenance even though it was not responsible for all the wear; London had streets that were too narrow, unlike continental cities; London's housing developments were too far away from tram routes; authorities were prejudiced against trams. The capital cost of replacing and updating the worn-out infrastructure and trams was also seen as prohibitive when compared with the £9 m capital cost of buying buses with a slightly smaller carrying capacity. "Operation Tramaway", the replacement of the tram service by diesel buses, was announced in July 1950 by Lord Latham of the London Transport Executive. Retirement started in October 1950 and London's final first-generation trams ran in the early hours of 6 July 1952 to a rousing reception at New Cross Depot. No general improvement in traffic flow was seen after the trams were withdrawn. During the closure cycle of London's tram system, almost 100 of the most modern trams known as the "Feltham" class and dating from 1931 were withdrawn and sold to Leeds where they continued in service until the abandonment of that city's trams in 1959. Some London tramcars have been preserved on static display at London's Transport Museum (in Covent Garden) and in working order at the National Tramway Museum at Crich, Derbyshire. A working London tram can also be seen and ridden on at the East Anglia Transport Museum in Carlton Colville near Lowestoft, Suffolk. Current trams The current generation of trams started with the opening of Tramlink in 2000. Croydon previously had many tramlines. The first to close was Addiscombe – East Croydon Station route through George Street to Cherry Orchard Road in 1927 and the last Purley - Embankment and Croydon (Coombe Road) - Thornton Heath routes closed