 Frank Pick , Managing Director of the Underground Group from 1928 and the Chief Executive of the LPTB , aimed to move the network away from freight services , and to concentrate on the electrification and improvement of the core routes in London . In particular , he saw the lines beyond Aylesbury via Quainton Road to Brill and Verney Junction as having little future as financially viable passenger routes . On 30 November 1935 the last train ran on the Brill Tramway between Brill and Quainton Road , and at the stroke of midnight , the rails connecting the Tramway to the main line were ceremonially severed . The former Aylesbury and Buckingham Railway between Quainton Road and Verney Junction was closed to passengers on 6 July 1936 , and London Transport services north of Aylesbury were withdrawn . 
