London Underground at +420 V, giving a potential difference of 630 V. On the sections of line shared with mainline trains, such as the District line from East Putney to Wimbledon and Gunnersbury to Richmond, and the Bakerloo line north of Queen's Park, the centre rail is bonded to the running rails. The average speed on the Underground is 20.5 mph. Outside the tunnels of central London, many lines' trains tend to travel at over 40 mph in the suburban and countryside areas. The Metropolitan line can reach speeds of 62 mph. The London Underground was used by 1.379 billion passengers in
Upminster road terminating in the town. The M25 motorway is located about to the east of the town centre. Havering Council's urban strategy recognises that nearby Hornchurch is the main cultural hub of the borough with a large theatre and arts spaces, and Romford offers the largest regional concentration of entertainment facilities. Within Upminster is New Windmill Hall, a flexible entertainment space, built in 1968, which holds up to 300 people. Upminster forms part of the tourism strategy for the borough. It is the location of Upminster Windmill, one of the few remaining mills in Greater London and is Grade II*