As global air traffic expands at record rates, experts warn that near misses on the ground at overcrowded airports are becoming one of the most serious safety concerns in civil aviation. The danger arises when airports try to alleviate bottlenecks by adding runways. That leads to more taxiways intersecting the runways, raising the risk of accidental incursions — where an aircraft or vehicle becomes a collision hazard by venturing onto a runway being used for takeoffs and landings.

"Runway incursions are right at the top of our agenda," said Gideon Ewers, spokesman for the International Federation of Airline Pilots' Associations. "They are happening more and more frequently as air traffic increases and older airport designs struggle to cope. Of course most incursions pass without incident, but when they do occur the results are very bad indeed," Ewers said.

The deadliest disaster in aviation history occurred 30 years ago as a result of such an encroachment. The ground collision in 1977 between two fully loaded Boeing 747s in Spain's Canary Islands killed 583 people. Since then, numerous such accidents have ended in tragedy and experts are now racing to develop systems to prevent even deadlier disasters.