But Heathrow, the world’s busiest airport, is a nightmare: crowded, congested, and dilapidated. And travelers are hamstrung by a recent British security edict that limits passengers making connections to just one carry-on bag, even if they’ve arrived from America with the standard complement of two pieces of hand luggage.

“The one-bag issue is really a competitive problem for us,” admits Robin Hayes, a native Londoner and executive vice president of the Americas for British Airways, by far the largest carrier at Heathrow. “We’ve definitely noticed that business travelers who would normally connect in London for an onward flight are now flying through Frankfurt, Munich, Amsterdam, and even Paris.”

But with Heathrow, at least, there’s hope for improvement. Led by airlines that have a vested interest in keeping it Europe’s primary connecting hub, groups are lobbying the British government to allow travelers to carry on two bags again. (Last week’s terrorist incidents in London and at Glasgow Airport may have slowed down that momentum, however.) - portfolio.com