The southwest option is more complex, requiring demolition of the village of Stanwell Moor and the reduction in size of two nearby reservoirs. The northwest runway option would see the elimination of two villages, Harmondsworth and Colnbrook and interestingly, Waterside, the headquarters of British Airways. Both solutions would also require burying parts of the U.K.'s busiest motorway, the M25 Orbital, so runways and taxiways could be built on top.
Heathrow's management also says the options could be mixed to allow a fourth runway; one would put two runways at the northwest site. All options include the development of new terminals and satellite buildings in line with the company's plan of giving the airport a more efficient “toast rack” layout, but the design could result in lengthy taxi times, similar to those seen at Amsterdam's Schiphol Airport.
Nonetheless, Heathrow continues to argue that an airport in the Thames Estuary would be a poor value for the money, and an inferior substitute with a smaller catchment area than Heathrow, resulting in increased travel times for passengers even with a major investment in transport infrastructure.
Heathrow officials argue that a Thames Estuary airport probably wouldn't be operational “before 2034,” and “could cost £70–80 billion, of which at least £25 billion would need to be funded by the taxpayer.”
“Adding capacity at Heathrow avoids the transition costs of moving to a new airport,” says the airport's owner. “The developers of a new hub airport would need to compensate the owners of Heathrow and airlines and airport companies as well as build new towns, schools, and hospitals to service the new airport's workforce.”
The company also claims the construction of the runway would provide economic benefits to the U.K. worth up to £100 billion.
But Gatwick officials have similar ideas for expansion. In proposals delivered to the commission on July 19, they say the U.K. doesn't need a hub airport and that capacity should be delivered across the “constellation” of London airports, not just Heathrow. In its filing, Gatwick Airport argues: “The U.K. does not have, and does not need, a so-called 'mega-hub' airport to maintain its global connectivity and status as one of the best-connected countries in the world.”
“Proponents of mega-hubs overstate the importance of transfer passengers in supporting London and the U.K.'s connectivity . . . Gatwick's further expansion will provide a feeder base that will, in turn, attract additional long-haul operations,” Gatwick officials contend. Airport studies indicate that transfer passengers represent only 13% of those using London's airports.
Gatwick has an advantage; it already has an area south of the airport set aside for runway development. It can also argue that its movements affect fewer urban areas because of the airport's position south of London.