Metropolitan line

The Metropolitan line is a London Underground route that extends beyond Greater London into Hertfordshire. It runs from Aldgate in the City of London to Amersham and Chesham in Buckinghamshire, with a branch to Watford in Hertfordshire. Printed in magenta on the tube map, the line is 41.4 miles long and serves 34 stations. Almost 94 million passenger journeys were made on the line in 2019. The line is one of two Underground routes that cross the Greater London boundary into the Home Counties. The line is the only Underground route with an express service at peak times. This allows trains to reach speeds of up to 62 miles per hour on some sections. The Metropolitan line began as the world’s first underground railway in 1863, running between Paddington and Farringdon with steam locomotives. It extended north-westwards into the Middlesex countryside, stimulating the development of new suburbs. Harrow was reached in 1880, and the line ultimately continued as far as Verney Junction in Buckinghamshire. A visitor finds a mix of above-ground and tunnel sections along the route. Between Aldgate and Finchley Road, the track lies mostly in shallow ‘cut and cover’ tunnels, apart from short sections at Barbican and Farringdon stations. The line shares tracks with other services on parts of its route, including the Circle and Hammersmith & City lines. Most of the route has two tracks, except for the single-track Chesham branch and a four-track section between Wembley Park and Moor Park.