The Man Who Pays His Way: One bag or two? The luggage laws that defy all logic

Short-shipped is one of those quaintly misleading phrases of which the aviation business is inordinately fond. Luggage that has been "short-shipped" has, in fact, not been shipped at all; it has been left behind at the airport where you checked in. Being the passenger mournfully watching an empty carousel trundle around is never a comfortable experience. Nor is going shopping for an emergency outfit in a strange city, as I recently discovered when trying to track down the district of underwear in the republic of menswear in the empire that is El Corte Ingls in Las Palmas in the Canary Islands.

From perspective of the airlines , reuniting passengers with possessions and paying out compensation is uncomfortable, too; the carrier that "short-shipped" the bag had to pay out more than the 55 I paid for my flight.

The UK's biggest airline, British Airways, would much rather that the "self-loading cargo" (that's us passengers) also brought its own baggage into the cabin, saving considerable costs in handling and mishandling luggage. BA has been infuriated by the government's uncompromising "one-bag rule", which it describes as "a serious inconvenience for passengers and not justified on security grounds". But from Monday, BA will be merely exasperated.

Most regular air travellers have become accustomed to the concept of uneven allowances. Flying out of the UK, no one is permitted to take more than one piece of luggage through security; this has prevailed in Britain since an alleged terrorist plot was uncovered in 2006. But coming home, security officials will cheerfully allow you to bring two or more through the checkpoint. The decision on how much hand luggage you can carry for a flight to Britain rests solely with the airline: BA says two pieces, easyJet and Ryanair only one. On Monday, 7 January, though, life gets even more complicated.

On that day, 22 British airports may abandon the one-bag rule. They have been deemed competent at processing passengers who turn up burdened with baggage. The Department for Transport says that the lucky 22 airports possess "sufficient screening capacity whilst being able to maintain the security standards that we require".

Travellers of the world, rejoice. But not too strongly. Because this arrangement is deeply flawed.

That 22 should actually read only 14. For a start, six are small Scottish airports: Benbecula, Islay, Kirkwall, Stornoway, Sumburgh and Wick. They may be able to handle the worst that we passengers can hurl at their X-ray machines, but since all the airlines serving this golden half-dozen allow only one piece, this commendable achievement is purely academic. Cambridge and Southend should be struck out, too, because they handle a negligible number of passenger flights. Which leaves a first XIV best described as a ragbag.

Scotland's main airports all make the list, but Northern Ireland's do not. To the south and west, Cardiff, Plymouth and Southampton have made the cut; but their busy respective rivals Bristol, Exeter and Bournemouth have not. Birmingham and Manchester are on board, East Midlands and Liverpool are not. In the capital, only three out of five airports qualify: Heathrow, London City and Stansted. Fly from Gatwick or Luton and the "one-bag rule" still applies. Such disarray adds a new complexity to air travel. BA must teach transfer passengers heading from, say, Rome to Houston that the amount of cabin baggage allowed depends on whether they change at Gatwick (one) or Heathrow (two). BMI has to explain that flying north from Heathrow to Leeds/Bradford or Durham Tees Valley offers a more generous allowance than heading south.

Among befuddled passengers, I predict a New Year boost in sales for coats of many pockets. These garments will allow passengers to wear their cabin baggage, rather than risk checking it in with possible embarrassment in the underwear department.

JUSTIN WEBB, the BBC's North America editor, is a wise man. In Correspondents' Look Ahead on Radio 4 last weekend, he predicted that this year will see "a resurgence of interest in, and affection for, America".

We agree: starting next week, each edition of The Independent Traveller will carry a story from one of the 50 states in the Union.

The phrase "special relationship" characterises more than a propensity for our political leaders jointly to wage ill-judged wars; it also describes the deep affection among the British and the Americans for each others' country. More than five million of us will fly the Atlantic this year, enduring the increasingly uncomfortable tangle of US red tape in return for rich rewards. The attractions range from spectacular skylines to the greatest outdoors, via theme parks, beaches, historic towns and lonely battlefields.

Our year-long sequence of state stories starts next week in Arizona, where our very own cowboy, John Walsh, tests the advisability of adopting "Wayne" as an alternative surname. Future highlights include Marcel Theroux in Louisiana and Joanne Harris in Hawaii, while Complete Guides will brief you on the delights of less-travelled states such as Kentucky and Maine.

The appetizer for our 50 slices of American pie begins on the next page: Leonard Doyle prescribes an exploration of Washington DC, the ragged diamond of territory that serves as the power base of the world's mightiest nation. Yet it remains sufficiently homespun that, on any working morning from 9 to 10.30am, you can wander into the cafeteria of the Supreme Court guardian of American constitutional liberties for breakfast.