United Kingdom planned and proposed metro lines. Future underground routes and rapid transit expansion projects before construction begins.
United Kingdom metro and subway lines formally proposed or in active planning: future underground corridors announced, studied or included in urban transport master plans but not yet under construction. Shows where cities plan to extend rapid transit coverage — new orbital lines connecting suburbs without routing through the city centre, extensions to areas beyond the existing network and entirely new metro systems in cities currently without subway.
United Kingdom has 219 proposed railway segments including 160 railway, 37 tram, 3 metro and 19 light rail.
Last update: 2026-06-20