I have seen much expansion of the London Underground network during my lifetime but never on the main line that I use and have used most of my life - the Metropolitan. The changes include the all new Victoria Line, the Piccadilly extension to Heathrow, the Jubilee gaining its independence from the Bakerloo and pushing out via London Bridge to Stratford, the Docklands Light Railway - a brand new system running over many disused mainline tracks and now the Overground line that provides a sort of outer-Circle through the suburbs. But nothing on the Met - indeed it shrank because services beyond Amersham to Aylesbury ceased in 1961. However it is finally expanding again because the Watford branch is to be extended to run up to Watford Junction, with two new stations on the way. The old Watford station will close. Work will begin next year and since nearly all of the route uses a disused mainline, should not take too long, although some spectacular new bridges will be needed.
Hitherto Watford has only been easily accessible by car from beautiful Ruislip. It will be nice to have the option of taking the Met there.