Population rise to make tube 'inoperable' within 15 years

London's soaring population could make the city underground tube network inoperable within 15 years, a senior tube manager has warned.

In comments to engineering researchers at Imperial College London, reported by The Times (£), Miles Ashley, the Tube's programme director for construction said the growing numbers of people using the tube each year was an "incredibly serious problem". He said overcrowding is threatening to make the system "inoperable" within 15 years.

1.3 billion people used the tube in the past year, he said, compared to 800 million in 2002. Transport for London projections have found that by 2026, 30 stations across London would experience crowding greater than four people per square metre, by 2031, this would rise to 50 of the 62 stations in London. A square foot is the average size of a telephone box - so each passenger would feel as if they were squeezed into a telephone box with three and a half other people.