So I just traveled to Portsmouth, VA for an experimental conference - in the sense that I don't expect conferences of this type to prove productive, but maybe I should try at least once - in the unlikely event that there are any local Overcoming Bias readers who want to drive out to Portsmouth for a meeting on say the evening of the 20th, email me - anyway, I am struck, for the Nth time, how uncooperative people are in getting off planes.

Most people, as soon as they have a chance to make for the exit, do so - even if they need to take down luggage first.  At any given time after the initial rush to the aisles, usually a single person is taking down luggage, while the whole line behind them waits.  Then the line moves forward a little and the next person starts taking down their luggage.

In programming we call this a "greedy local algorithm".  But since everyone does it, no one seems to feel "greedy".

How would I do it?  Off the top of my head:

"Left aisle seats, please rise and move to your luggage.  (Pause.)  Left aisle seats, please retrieve your luggage.  (Pause.)  Left aisle seats, please deplane.  (Pause.)  Right aisle seats, please rise and move to your luggage..."

There are numerous other minor tweaks that this suggests, like seating people with tight connections near the front left aisle, or boarding passengers with window seats before passengers with middle and aisle seats.

But the main thing that strikes me is twofold:

First, everyone who stops to take down their luggage while everyone waits behind them - as opposed to waiting to rise until the aisle is clear - is playing a negative-sum game; the benefit to themselves is smaller than the total cost to all the others waiting in line.

Second, the airline has a motive to clear passengers quickly to reduce turnaround time.  But the airline does not regulate the deplaning process.  Even though it would be straightforward - defectors being readily spotted - and I don't even see why it would be resented.

Am I missing something?  Is there some mysterious Freakonomics-style explanation for this?

Heck, people usually manage to regulate themselves on worse cases than this.  Most of the people blocking the aisle wouldn't walk away with someone else's purse.  Are we just stuck in an equilibrium of mutual defection?  You'd think people not in a rush would be willing to unilaterally wait until the aisle is clear before getting up, as it's an inexpensive way to purchase a chance to feel quietly virtuous.

If an essentially friendly crowd of human beings can't cooperate well enough to walk off a damned plane... now really, we should have more pride as a species than that.

New Comment
35 comments, sorted by Click to highlight new comments since:

People nearer the front think that they have the moral right to get off earlier than people behind them, regardless of whether they got their seat through choice or chance. People also like to get off with the other members of their party.

So people nearer the front will defect from this solution even though all but the first half dozen rows would probably be better off cooperating. Once all the people in front of passenger X have gotten off, passenger X will defect as well.

I'm seldom in a hurry to get off the plane (I know there's just more waiting once you're off) so I wait till there are gaps in traffic to get out of my seat and retrieve my luggage. Of course I can only get away with this if I have my preferred window seat. Otherwise, in deference to the greedy (but conventional) expectations of the people I'm trapping next to me, I have to get off as quickly as I'm able.

Even though it remains unproductive, I think you've overlooked the main reason why this phenomenon occurs. Although greediness may play a large role in determining many of our situations, deplaning is done using the same procedure as "debussing" or "de-exiting-any-venue-with-aisle", right? So the prevailing rule isn't "be as greedy as possible", but rather "adhere to the most commonplace rule", which happens to be unusually ineffective due to difficulty in retrieving luggage.

The worst part about it is certainly that some people on the plane are actually in a rush. A simple announcement over the intercom to allow those trying to make connecting flights to exit first could ease the situation.

I haven't thought about this in-depth, but I almost always wait a while before I try to get off the plane.

Usually there is a period of time between when people can rise from their seats and the door opens. So if it was possible for folks to get their luggage then that would be the perfect time. The problem seems to be that some people can't get to their luggage until other people get out of their way. I don't see how telling the left side to get their luggage first solves this problem.

Personally, I pretty much always have checked baggage, I can always make it to baggage claim before my luggage does, so I don't really care about saving time getting off the plane. If I'm in a window seat I usually let people behind me get off first, but if I'm in an aisle seat I don't want to block in the person in the window seat.


"I don't see how telling the left side to get their luggage first solves this problem." He said left aisle.


Maybe people have the idea that the line moves slowly, and that they can't cut in line. Thus if the front of the line gets past them, they have to wait until the entire line is gone before exiting.

This is the species after which EY is trying to pattern fAI. Thank (God, goodness, whatever) that the Bush opponents to advances in science are unlikely to see this post, which is the dumbest I have yet come across on OB, and which confirms that EY is just a person, like the rest of us.

I've read about ideas for boarding planes in a similar way, and a thought/issue that occured to me with that applies here too:

Wouldn't one have an issue with groups of people that are traveling together being separated more using your method? (Especially note families (parents and young children))


J. Steffen. Optimal Boarding Method for Airline Passengers (copy on request). 2008. Journal of Air Transport Management. M. Bazargan. A Linear Programming Approach for Aircraft Boarding Strategy (copy on request). 2007. European Journal of Operational Research. Vol. 183, pp 394-411. E. Bachmat, D. Berend, L. Sapir, S. Skiena, and N. Stolyarov. Analysis of Airplane Boarding via Space-Time Geometry and Random Matrix Theory. 2006. Journal of Physics A: Mathematical and General. Vol 39, pp L453-L459. P. Ferrari. 2005. Improving passenger boarding in airplanes using computer simulations. International Airport Review. M.H.L. van den Briel, J.R. Villalobos, G.L. Hogg, T. Lindemann, and A. Mulé. 2005. America West Develops Efficient Boarding Strategies (copy on request). Interfaces. Vol. 35, No. 3, pp 191-201. M. Pan. 2004. Efficient boarding procedures for midsized passenger aircraft. (highschool graduation project) E. Bachmat, D. Berend, L. Sapir, and S. Skiena. 2004. Airplane boarding, polynuclear growth, disk I/O scheduling and space-time geometry. F. Pieric, and K. Nagel. 2004. Robustness of Efficient Passenger Boarding in Airplanes. M.H.L. van den Briel, J.R. Villalobos, and G.L. Hogg. The Airfcraft Boarding Problem. 2003. In Proceedings of the 12th Industrial Engineering Research Conference (IERC-2003), Nr 2153, CD-ROM. H. van Landeghem, and A. Beuselinck. 2002. Reducing Passenger Boarding Times in Airplanes: A Simulation Based Approach (copy on request). European Journal of Operations Research. Vol 142, No 2. pp 294-308. S. Marelli, G. Mattocks, and R. Merry. 1998. The Role of Computer Simulation in Reducing Airplane Turn Time. Aero Magazine. No. 1.

Psy-Kosh, if the directions were changed from an order (Left aisle seats, please retrieve your luggage) to a permission (Left aisle seats, you may now retrieve your luggage), that problem would go away, and it may not have a tremendous impact on the efficiency of the algorithm.

Rather I suggest a market solution: since carry-ons increase plane weight and are a hassle for passengers, security, and airline staff all, why don't the airlines reduce the cost of the flight for those who bring no carry-ons? Maybe by US$50?

This would probably be enough to incent people to bring fewer if any carry-ons, thus speeding both boarding and deplaning. It also would probably increase flight security.

Generally unless it's an overnight trip, I FedEx my luggage to my hotel anyway and bring only my purse.

Even odder: why so much literature on boarding, but not on deplaning?

Because boarding is what can potentially delay a plane, while disembarking takes places when a plane has already arrived and cannot influence the flight's schedule?

In general a compulsion to apply regimentation to all things human carries just a wisp of intellectual insanity. The constant parading of intelligence can easily come to seem like preening.

The flipside of this is the inanity of Southwest Airlines employees with respect to boarding the plane:

As is well known, Southwest doesn't have assigned seats, so the choice of seating is determined by boarding order, with earlier people getting more choices. People want to avoid middle seats, so the natural tendency of later boarders on crowded flights is to keep walking as far as necessary toward the back of the cabin in the hope of finding and empty aisle or window seat. For some inexplicable reason, however, Southwest flight attendants and gate managers actively discourage this, wanting people instead to take the first middle seat they find. The all-too-predictable result is a traffic jam in the aisle and the jetway, as the line continually stops to wait for the leading person to stow their luggage and take their seat.

It should be obvious that, regardless of how crowded the flight is, boarding efficiency is maximized by having each passenger go as far to the back of the cabin as possible, to allow the line to keep moving forward. Is this goal somehow less important than that of teaching people not to vainly expect aisle or window seats?


Well observed Seinfeldski.

For self regulation I think the problem is there isn't a straight path to a more optimal solution.

In similar situations I generally try to wait in my seat until the congestion dies down (if I'm not in a rush). While I get the benefit of a more relaxing experience this has the effect of significantly delaying my departure.

But for a real solution I think you really need some simple modification you can make that benefits the group without significantly costing yourself. Other than delaying I can't really think of any other simple changes passengers would make that would move them in the direction of a more complete solution.

As to pilot organized optimizations I think this has to do first with the fact the airline wouldn't really benefit that much (the bottleneck would be refueling and maintainence, not disembarking) and the cost of seeming to order passengers around.

Btw, as to the proposed solutions.

"Left aisle seats, please rise and move to your luggage. (Pause.) Left aisle seats, please retrieve your luggage. (Pause.) Left aisle seats, please deplane. (Pause.) Right aisle seats, please rise and move to your luggage..."

Families who don't want to break apart would break this algorithm and explaining exceptions would be too complicated.

"There are numerous other minor tweaks that this suggests, like seating people with tight connections near the front left aisle, or boarding passengers with window seats before passengers with middle and aisle seats."

Similarly these also have issues with breaking apart families or inducing a cost of forcing people away from their preferred seats (I'd rather sit in my preferred seat than get off the plane quickly).

I wouldn't be surprised if all solutions had similar costs.

I always hated the wait in the aisle for that process.

It's true people stop at red lights (usually) but there's a fear of punishment.

Last time I flew, the pilot asked the passengers to put their shades down after we landed to cool the plane down. Well, I noticed 10% who complied.

So I don't know if that anecdote adds anything to the discussion...but people can be selfish.

This is like the crowded bus or train syndrome, where everyone clusters close to the exits, thus increasing the effective crowding, and making it harder for cooperators to move into the empty space further inside the vehicle.

"I haven't thought about this in-depth, but I almost always wait a while before I try to get off the plane.

Posted by: jsalvati | August 18, 2008 at 09:27 PM"

If you have a window seat, that's fine. Otherwise, move it and quit being a pinhead. I spend a lot of time trveling and I'm always amazed at the quirky behavior of people. People who take off their shoes and inflict their fungal emanations on the rest of the cabin are the worst. For some reason, people in 1st/business class do this more often than coach. Also, placing your stinky feet on the bulkhead in front of you should call for removal of at least one toe. Another thing is the selfish idiot (sorry to say, it's usually a female) behind you who sees the magazine pouch as their own personal cubby hole to constantly fiddle with their water bottle, thick paperback book, U-shaped airplane neck pillow, etc... So, deplaning is usually a relief just to get away from these vile people.


  1. Rear window seats first, then middle windows, then front
  2. Everyone asked to take their seat and sit down without stowing their hand luggage
  3. Everyone asked to stow their luggage
  4. Repeat for aisle seats

Reverse procedure for disembarking

The margin for what is considered reasonable makes this hard.

For example, ten briefcase holding passengers, ready to leave the plain, would probably urge someone to make room when they start to reach for the first bag of a total of seven while blocking the way.

Some people will not want to hold up a line when they judge their actions will hold up the line for a long time. But at some point you have to get up, you cannot stay in the plane and not everyone can be last :D.

But it must be frustrating if you are ready to walk out the plane, that fellow passengers decide it is reasonable to start blocking your way.

The strategy "proceed as far as possible in the moment without any long term planning or cooperation" is quite common, not only in exiting planes and buses:

You can grab your carry-on baggage while staying out of the aisle entirely. It's not hard.

If it takes longer to unload the checked luggage than for everyone to deplane, then turnaround time will not be improved.

(It's a nicer conference than I expected so far, remains to be seen if it'll be productive.)



Since carry-ons are fewer and lighter (to lug around) than checked baggage, and it takes quite a lot of time to retrieve your checked baggage, there is actually tremendous incentive for people to take only carry-ons with them (especially for short trips). Plus, there is no risk of lost baggage in such cases.

I would rather spend 5-7 minutes waiting on my seat in the plane or standing in the aisle (I don't get out in the aisle unless I am sitting on the aisle/middle seat, and even then I ask the passengers in my row if there really would rather stand and wait than sit comfortably) than wait for 20-30 minutes in the baggage retrieval area waiting for my suitcase.

A related factor that has been mentioned to me is that after sitting in their cramped seats for quite a while, many people just want to stand up and get the circulation going in their legs. They don't really mind standing and waiting.

[The fastest way to board a plane is to] have 10 passengers at a time board in alternating rows. He says it's at least four times faster than what most airlines are doing because it lets everyone stow their luggage and take their seats without getting in one another's way.

I am surprised no-one this far has mentioned the (irrational) impulse of aisle seat passengers to make room for middle and window seat passengers to get out. Whenever I get the aisle seat, I have to fight the primate part of my brain that tells me that the passengers behind me in line want to move on, that I am keeping them from moving on, and that they are annoyed by my behaviour.

I know intellectually that deplaning won't happen any faster if I get up early, but if I do, the blame for the slowness then appears to lie with whoever is blocking the aisle between me and the exit, and not with myself.

This kind of social pressure may to a great extent explain why deplaning behaviour is the way it is.

For most people on the plane, it doesn't matter. Whether you're the first person off the plane or the last, you'll get your bags off the conveyor belt downstairs at roughly the same time. You as an individual do have the option of not getting up the line has been unclogged--good for getting in a few more pages of whatever you're reading--but that doesn't really help everyone else.

Well, over here in Malaysia, people don't even line up to board trains. My pet peeve is that on one of the inner-city train systems, there is a pole rooted between the floor and the ceiling of the train, RIGHT IN FRONT OF EVERY DOOR. You can imagine what then happpens - commuters walk into trains, grab on to the pole, and stand absolutely still, such that no one else can get in. It's a design flaw that's existed for 10 years now, I think.

"How would I do it? Off the top of my head:

\"Left aisle seats, please rise and move to your luggage. (Pause.) Left aisle seats, please retrieve your luggage. (Pause.) Left aisle seats, please deplane. (Pause.) Right aisle seats, please rise and move to your luggage...\""

To me, getting off the plane fast is less important than watching everyone who may touch my luggage.

Many planes have unequal ratio of storage area to seats on the left and right, and water bottles and various things are already in some of them. People sometimes put their luggage on the side opposite of their seat and/or more forward or backward than expected. It is common for people on both sides of the plane to open their opposite storage area.

If I had a window seat and could not see where I put my luggage, I would want to stand up immediately to watch it. If I did not, it would be easy for someone to unzip parts of it and move 1 thing to their luggage.

Many people will say I am paranoid or need to trust people more or that the punishment for stealing on a plane is so high that it would be rare. They may be right, but neither of us has calculated the chance of that, and waiting an extra few minutes on each flight, summed over all flights I will ever take, takes less time than to calculate that. I would not save any time in the best case. If a small number of people could do that calculation and everybody believe it, time could be saved, but I could not believe them without taking the time to calculate their motivations, and that would also take more time than I could save.

Hi, it is funny that I am actually looking for literature about the deboarding/deplaning Process and this discussion is the only thing I found. I do a research about deplaning for university. It includes literature research (haha, not so funny..) and simulation part. It really seems, that it is not possible to improve deplaning time with ordered deplane methods. I probably not allowed to give more information here,yet. but I will ask if I can and post it.

You'd think people not in a rush would be willing to unilaterally wait until the aisle is clear before getting up, as it's an inexpensive way to purchase a chance to feel quietly virtuous.

Yes, that's what I usually do, and I know I'm not the only one. But ISTM we still are less than 5% of the people on an average plane.