In the mid to late 20th century, British Rail express services compared unfavourably with France's TGV and Japan's Shinkansen. Experience with High Speed Trains on the East Coast Main Line from London to Edinburgh had shown that reduced journey times could produce a significant increase in passenger numbers, but that line was largely straight and suited to high speeds. Other lines, such as the West Coast Main Line (WCML) from London to Glasgow, were not straight enough to support high speeds with conventional equipment. Lateral forces would be just too high around corners; passengers would not be able to stand upright easily, and items would move on tables. Because slower trains also use the same tracks, superelevation (banking or "canting" of the track around curves) could only be utilise