 Greengauge's plan calls for two north/south corridors from London, which would broadly parallel the ECML and WCML, together with three east/west corridors between London-Bristol, Sheffield-Manchester and Edinburgh-Glasgow.Both the north/south lines would consist of new-built high-speed lines, while the east/west corridors would run on existing lines upgraded to allow 200 km/h running.One of the central parts of the Greengauge 21 proposal is to have it linked directly with High Speed 1, to allow through running to the Channel Tunnel, thus enabling trains to run direct from regional cities to Europe.