When boarding airplanes, different airlines have different policies. The most common policy adopted by airlines is to board passengers by seat rows starting from the back. This makes a kind of intuitive sense. A few airlines have some kind of zone system. About three years ago, a physicist studied the issue using Monte Carlo simulations came up with a plan that can cut boarding times by half.
He found that the most efficient boarding method is to board alternate rows at a time, beginning with the window seats on one side, then the other, minimizing aisle interference. The window seats are followed by alternate rows of middle seats, then aisle seats. He also found that boarding at random is faster that boarding by blocks.
According to his estimates, this saving of time can lead to savings of over $100 million per carrier. According to this site, in the US only United has adopted something close to the window-middle-aisle scheme, while Southwest and US Airways have some kind of random seating.
So why haven’t these plans been adopted more widely three years later? I can think of several reasons other than simple inertia on the part of the airlines.
One is that as far as passengers are concerned, the time taken to board is among the least aggravating factors in air travel so changing it will not increase customer satisfaction by much.
Another is that people want to have a reasonable shot at getting space on the overhead bins for their luggage. If those in the aisles were always last to board, that would influence seat choices. Of course, the airlines could use that fact to nickel-and-dime people even more by charging a premium for window seats.
But what about random boarding? That sounds easy to do and fair. But even if it saves time, I would not like it because then those aggressive people who like to be the first to board for whatever reason will strive to be near the top of the line while those of us who don’t like to compete with others for positions in line will always end up at the back of long lines.
Ultimately, I think the main purpose of any boarding scheme is to have people line up in small numbers. There is something quite dispiriting about seeing really long lines.