Physicist cuts plane boarding time in half

http://news.cnet.com/8301-17938_105-20099450-1/physicist-cuts-plane-boarding-time-in-half/

by timf • 15 years ago

197 110 15 years ago

news.cnet.com

cliff• 15 years ago

I remember seeing this before.

I think it's really cool, though in the article I read before one major block to implementing this is that you'd be splitting up group boarding (of even 2 people travelling together).

I feel like that might be a tough message to try to explain to everyone at the airport, since in general people are worried about everyone in their party making it on the plane safely and with all their stuff. Gate agents have enough worried customers as it is.

colonelxc• 15 years ago

Yes, the main problem with this method is that it is socially unacceptable to split up families and groups while they wait to board and are boarding.

I think a slightly less efficient approach would be to somewhat batch up rows. So instead of having all of the people in the window aisle on one side of the plane enter, how about have 1 row of people (typically 3) on one side of the plane. Instead of doing every row at once, do every 3rd or 4th row. That way, the same amount of people will be in front and behind you as before (including moving up far enough to be out of your way when the group of 3 in front has reached their row). So then you can alternate sides of the plane, and also alter what set of rows on each side (basically, if 0 == row modulo 3, then you are the first set of rows to board).

Regardless of how anyone decides to partition passengers, however complicated, the computer just needs to make sure to number boarding passes accordingly so people can line up in whatever order you choose. Southwest kinda has that going on (your boarding pass has an A,B,C and a number 1-60 on it), but the letter/number is based purely on what order the passengers checked into their flight (and on southwest people get to sit wherever they want).

steve-howard• 15 years ago

The family part could also borrow from Southwest; there, families board in between numbers (special preboard/unattended minors go before anyone at all, families in general go after business select). Although since we're assuming that the seats are assigned here, the families should probably go last (they take longer to get settled).

davvid• 15 years ago

Another simple solution would be to board from back-to-front. Right now it's front-to-back: the business-class passengers (at the front of the plane) board first. Economy class boards last and each passenger has to walk through the congestion.

Getting business-class travellers to give up their sense of entitlement and board last could be a little tricky, though. I'm sure there's a psychological marketing trick that could be used to make them happy about boarding last. Maybe something along the lines of, "You're special. Boarding starts 10 minutes later for business-class. Take your time" or something.

roel_v6• 15 years ago

But you don't have to implement to scheme perfectly to get major efficiency gains. Just give everybody in the same party the same color / let them board in the same group, and swallow the minor hit that it causes on boarding times.

OK it still wouldn't work for groups who don't check in at the same time, but those would likely have seats in other parts of the plane already anyway (unless they checked in online, in which case you could group them there...)

kemayo6• 15 years ago

Boarding by blocks starting at the front is ridiculous.

In fact, I'd be hard pressed to think of a worse way to board a plane. And yet somehow every time I fly that's how it happens. Maybe it's just that my company chooses horrible airlines.

The article mentions that assorted methods of boarding were tried, though it only goes into detail about "the Steffen method". I wonder what the difference between blocks-from-the-front and the obvious improvement of blocks-from-the-back is.

jbri2• 15 years ago

The difference is generally that higher-paying (i.e. first and business class) passengers get seated first (because having your higher-paying passengers wait for the lower-paying passengers is undesirable), and they're also generally seated at the front of the plane so they don't have to wait when getting off either.

kemayo6• 15 years ago

Though back-to-front means that the expensive passengers can arrive closer to the departure time, and don't have to suffer through everyone in economy shuffling by them and hitting them with their carry-on.

It does cost them some flexibility, in that they can't board as soon as they arrive. But my experience is that sitting outside of a plane is generally far nicer than sitting in first class... at least on domestic flights. For international flights getting on sooner would be more desirable.

amalcon• 15 years ago

At least one U.S. airline (I forget which) briefly used a transparent scheme to work around this: the first class rows were boarded first, and from there was back to front.

______• 15 years ago

I think part of the reason that people could justify the expense of first class is exactly this -- the ability to sit there with a smug look while the rest of the plane exasperatedly waits to be seated.

kemayo6• 15 years ago

I'm prepared to admit that I am not motivated by this.

To me it sounds far more pleasant to sit there outside reading while everyone else has to queue up, then walk in just before take-off to get into my comfortable first class seat, without being jostled by the entire rest of the plane's passenger complement slowly trudging past me and impinging on my personal space.

Perhaps I'm weird.

mikeash2• 15 years ago

I once got bumped up to Business Class and the experience sorely tempted me to spend the extra money in the future. It had nothing to do with smugness and everything to do with a seat that isn't painfully small, enough legroom to avoid being horribly cramped, ability to recline more than five degrees, and food that didn't make me want to vomit in terror.

joshwa3• 15 years ago

Smugness isn't the word. It's more about having the whole experience be less stressful. I just made elite status for the first time, and being able to skip the lines, get my choice of seat (even in economy) makes a huge psychological difference.

I can settle into my seat, and do some work before the door closes, or even fall asleep before the wheels leave the ground.

Also, lounge access. Lounges make air travel civilized, like staying at a nice hotel (SFO international British Airways lounge excepted— it feels like being at a Holiday Inn Express).

(I'll fly 75k miles this year. AA PLT/OW Emerald, and I fly almost exclusively CX/KA/AA.)

hermannj314• 15 years ago

Not to diverge too much from the topic. At JFK, the first class passengers have a priority queue through the security system as well. I flew through JFK once on a Holiday (4th of July) and TSA was so understaffed that they barely had enough staff to handle the 1st class passengers that were arriving.

So as if waiting in security lines were not enough, imagine waiting in a security line that was actually getting longer as you just sat there holding your bags watching first class after first class passenger go through and everyone else just standing there.

I just couldn't understand why the TSA would even care about the class status an airline gives to its passengers, I don't know any other airports that do this.

DaveMebs• 15 years ago

I don't think that boarding back to front is the necessarily an obvious win here. One thing you will see on flights is that people in the back often place their overhead bags in a compartment near the front. As they do not plan to access this during the flight, it causes them no trouble and saves carrying the bag back and forth. The downside, of course, is that people in the front quickly run out of overhead space while there is still plenty of room in the back. Shuffling bags back and forth is obviously costly and depending upon the prevalence of this behavior may result in less efficient boarding (as compared to front to back).

rorrr• 15 years ago

Still, on average, back-to-front is faster.

zacharycohn• 15 years ago

You could discourage this behavior by keeping overhead compartments closed when passengers board the plane. As they reach their seats, then they open a compartment for their bag. Once everyone is seated, staff closes all the compartments.

I think the added time/social pressure having to open a compartment would be enough to stop most people who do this.

LiveTheDream• 15 years ago

The source paper: http://arxiv.org/abs/1108.5211

stretchwithme2• 15 years ago

Imagine how much boarding time could be slashed if robots handled the baggage. The line stops moving when people are trying to store their bags, even if stepping aside for a moment would significantly reduce delays for others.

joeyh2• 15 years ago

If the airlines cared about this problem, they could eliminate much of it by dropping the checked baggage surcharges. Enormous bags that barely fit or whose owners can't lift them was IIRC not as much a problem 12 years ago, when checked luggage was free.

roel_v6• 15 years ago

I think the delays in boarding are cheaper than what they need to pay the airport for the luggage handling.

stretchwithme2• 15 years ago

Or they could charge for both services. Or charge a fee fr total poundage of passengers and their luggage.

Yeah, it has become more awkward to board since they imposed these fees. I switched to a smaller bag so I could carry it on.

And I fly Southwest when its possible. They don't have fees for the first few bags and their boarding process has actually gotten better in the last few years.

arturadib2• 15 years ago

Classic example of "cracking a nut with a sledge hammer". You don't need Monte Carlo to understand that boarding first rows is less efficient, or to come up with a much more efficient procedure. (And this is coming from a Monte Carlo lover).

What you do need is biz savvyness to understand that rows are ordered by passenger value (first and biz class first, followed by premium, platinum, frequent flyers, etc). These passengers pay a high premium to board and deplane first. Airlines are not going to lose these valuable passengers for a gain whose magnitude is uncertain at best.

njharman• 15 years ago

> Monte Carlo to understand

proved, not understood.

arturadib2• 15 years ago

You're still missing the point. It doesn't matter.

lojack• 15 years ago

> You don't need Monte Carlo to understand that boarding first rows is less efficient, or to come up with a much more efficient procedure.

Such as boarding from both the front cabin door and the rear cabin door?

tripa• 15 years ago

Adding boarding doors costs money too.

Nate75Sanders• 15 years ago

While we're on the subject of statistics, airplanes, and mathematically-but-not-socially-correct ways to do things, I really wish they'd have seats on the plane spaced according to a height distribution of passengers.

swhitt2• 15 years ago

Height distribution? I'd much prefer a wingspan-based distribution. There's nothing like getting stuck in a middle seat between two broad-shoulderd gentlemen.

whatusername• 15 years ago

You obviously don't have long legs.

johanbev• 15 years ago

That would be splendid. I'd even pay more if i can get room for my legs, but much more importantly have the opportunity to actually lean back in the seat and not break my neck... In otherword have a neckrest that's not designed for 150cm tall people.

martingordon• 15 years ago

He should totally patent his boarding method. Who cares that it could save the airlines billions? He could rake in so much dough by licensing the method or suing airlines who use his method without a license! And if the patent is vague enough, he could probably collect on all the other inferior boarding methods too!

In all seriousness, the boarding problem only got worse once airlines started charging for bags as people starting carrying on more and more. I read somewhere that Southwest actually saves more money by offering free checked bags and saving on boarding time than they would make had they charged for free bags.

artmageddon• 15 years ago

I usually travel pretty lightly, but this is one reason that I love flying with Southwest.

madh• 15 years ago

Exactly. Most of the time is people dealing with luggage. I wish airlines other than Southwest were less myopic.

Plus don't forget all that time spent getting through airport security, especially with liquids and toiletries. Airlines should charge for carry-ons, not checked bags.

mef• 15 years ago

Boarding statused passengers first aside, it seems like this could be easily communicable with announcements of "boarding even rows", "boarding odd rows".

I skimmed the paper and didn't see any mention of how to get passengers to obey gate agent instructions, though, which would be a prerequisite of implementing an effective boarding method. Perhaps this should be re-tested by airlines randomly selecting sold out flights with identical planes to try these methods.

zeteo• 15 years ago

Looking at the paper, it seems the passengers were the same and boarded five times in a row, with the last two methods proving the fastest. The major experimental flaw seems to be that the passengers themselves might learn to become more efficient after concentrating on a normally rare task, and repeating it several times in a row. Also, since some of them were paid extras, they might just be getting impatient by the end, and rushing through at what would normally be an uncomfortable pace. The population sampling is also probably not representative.

I would have found the experiment more convincing if it had been used to validate the basic assumptions of the theoretical model instead (e.g. the statistical distribution of the baggage loading and seating times).

WalterBright2• 15 years ago

I participated in an FAA cert airline evacuation test once. Only participants who'd never gone down the slide before were allowed, and only one take was allowed.

(yeah, we passed!)

pangram• 15 years ago

These are good points (and there are other confounding factors, such as the fact that anybody taking part in the test would naturally be more familiar with block boarding). Nonetheless it seems like it might be worth trying out, as they do have some theoretical basis for the improvements.

city41• 15 years ago

There are other practical considerations too. I can't even imagine trying to organize the passengers in the airport such that they board in the alternating row, outside-in configuration.

And there's the pretty much insolvable problem of when they start boarding the plane, many people just get on and couldn't care less that their row/section hasn't been called yet.

aurelianito• 15 years ago

The first part is easy, color code the ticket (e.g. first red, then blue, etc). The second issue is trickier, but it happens now anyway. I would say that they already know how to handle it.

kd0amg• 15 years ago

I can't even imagine trying to organize the passengers in the airport such that they board in the alternating row, outside-in configuration.

I remember doing something similar with my high school marching band (back-to-front instead of window-to-aisle), but that's a pretty tenuous proof of concept.

raldi• 15 years ago

Southwest seems to have solved it.

JoeAltmaier• 15 years ago

Agreed. In my experience, big chunks of time are spent waiting for one person struggling with their gear, backing the line up clear out the door. The experiment subjects probably didn't role-play that scenario.

pyoung• 15 years ago

I am interested to know where they got the savings estimate. $110M seems like a bit much for cutting the boarding time by 10 to 20 minutes. I was under the impression that most airline delays were caused by weather and traffic, not boarding times.

joshwa3• 15 years ago

There's actually a fair amount of time spent on the taxiway by arriving planes waiting for gates. Sometimes they'll shutdown and wait, but often they're sitting there idling. That's a lot of fuel savings by reducing time spent waiting for gates.

Additionally, increased turnaround times means that airlines can fly (on a marginal basis) more flights per plane per day. On high-load-factor routes that increased revenue can be significant.

WalterBright2• 15 years ago

I'd try loading people without carryons first, as the carryon stowage is what keeps blocking the aisle.

jeffreyg• 15 years ago

I flew Virgin last week and they let people without carryons join with "Group A" for boarding.

kam• 15 years ago

Frontier does this.

wooswiff• 15 years ago

If you want to maintain preference towards first class and board from front to back, why not just use the door at the back of the plane?

herdrick• 15 years ago

I don't think you'd call this a Monte Carlo simulation. It's just an experiment.

Bud• 15 years ago

What a shock to read that despite this knowledge, the airline industry continues to do things the exact same way, wasting huge amounts of time and money and fuel in the process.

This really isn't a smart industry, in many respects.

psychotik• 15 years ago

This looks good in theory, but if you have a party of 2 or more people, who are presumably seated together, then it is practically impossible to get them to board at different times as the algorithm would want to. I don't know for sure, but based on anecdotal observation I would guess that at least 50% of persons onboard travel with a co-passenger. I think that will throw the algorithm off quite significantly.

jgfoot• 15 years ago

Airlines have been doing their own research into this, apparently. American Airlines is switching to randomized boarding (one of Steffen's proposed solutions) and United is partially switching to window-middle-aisle. http://online.wsj.com/article/SB1000142405311190423340457645...

jcampbell1• 15 years ago

No only that, they have been doing research into this for a long time. Below is an article from 2006, that references an implementation of a mathematical model in 2002.

http://www.nytimes.com/2006/11/14/business/14boarding.html

mgkimsal2• 15 years ago

I flew a few weeks ago and dialogued (argued? - tried to be good natured about it!) with the boarding staff at 3 different gates about boarding processes. I suggested they try windows first, then middle seats, then aisle seats. 2 out of the 3 argued back that the way they were doing it had been 'proven' by some study some years back by... either a Finnish airline, or some studies in Arizona - I honestly can't remember which they said (but they'd both said the same place). Very odd, because it's demonstrably pretty damn slow, and often the slowness is quite visible - people with window seats having to stop and climb over someone in the aisle and middle seats, causing a backup. Agreed, it's not the only cause of backups, but in my recent 6 flights, 5 of the boarding processes were rather significantly slowed by multiple window/aisle snafus.

As much as someone wants to say "we've studied this already, and this is the best way to do it!", you'd have a hard time convincing me that any major airline knows how to make good decisions about anything.

joshwa3• 15 years ago

Please don't harass the gate agents unless they look really idle. They don't have control over the boarding process, and they are desperately trying to get everyone on board, seat change requests accommodated, standby and upgrade list cleared, plane catered, wheelchairs, minors, gate checked baggage, strollers, etc., all the while dealing with a bombardment of impatient, indignant, overtired, and entitled "customers".

Be pleasant and let them do their job. I believe their job performance is measured by on-time percentage/turn time.

mgkimsal2• 15 years ago

I should have reworded this - it was pleasant as could be and typically about 10 seconds of conversation as they're scanning the boarding pass. It was more curious to me that 2 of them referenced a 'study' done - almost as if it was a talking point.

I try to be as fast and polite as possible in those moments, simply because I see many other people being rude/short with them.

And to the other point, yes, I understand they're not making the rules.

re: being measured by "turn around" time - I'd end up quitting if I was measured by a process which I had no control over (and even in low/minimum wage jobs, I've ended up doing so).

roel_v6• 15 years ago

Thing is that the boarding staff has as much say about this (and as much interest in improving it, for the most part) as the janitor has in what sort of flooring is in the building he's maintaining.

frossie• 15 years ago

Savings from sophisticated method to board plane faster: 110 million dolars

Getting passengers to board when (and only when) it's actually their turn: priceless

(and, I suspect, far trickier)

Zak• 15 years ago

Getting passengers to board when (and only when) it's actually their turn: priceless

Yes, exactly. I tend to wait for the final boarding call so as to spend less time in line and on a cramped plane.

nostromo• 15 years ago

If they could find enough room, I always wondered why they don't have a line for each group. So, if there are 5 groups, have 5 starting point lines.

mdhen• 15 years ago

I think Southwest definitely has the best system for this (numbered pillars to line up at), although it doesn't really apply to seating arrangements since SW is random seating.

Although that seems like a bonus as the random seating was the second best method.

SonicSoul• 15 years ago

this method seems to assume that people will line up in perfect order so that no one blocks anyone else, but that simply isn't the case. the alternating rows that were called would stagger in random order and blocking would occur as normal. probably enforcing less carryon would speed the process up the most, but they'd have to make the checked in baggage pickup quick and easy to give people more incentives to check in.. maybe even offer a service that picks up rollies right at the gate and makes the available after getting off the plane..

matthew-wegner• 15 years ago

My solution: Offer free drinks if everybody can board in <X minutes. Social pressures will do the rest (I occasionally see people help load heavy bags overhead, but I imagine this would pick up).

Not entirely joking!

tesseract• 15 years ago

Will that get people to cooperate or will it just get them to trample each other? I'd be worried people would just hear "free drinks if you get on the plane quickly" and ignore the part where it needs to be everyone.

Or you might just get a teetotaler blocking the aisle.

teyc• 15 years ago

The delays I experienced is usually due to one or two passengers trying to get their last cigarettes before boarding.

Furthermore, there is no point getting too geeky about complicated boarding sequence if passengers are going to get unhappy over it.

Better to do a Steve Jobs and keep things simple.

synacksynack• 15 years ago

Menkes van den Briel did some work on airplane boarding. He has really nice explanations and videos here: http://leeds-faculty.colorado.edu/vandenbr/projects/boarding...

rmc• 15 years ago

I don't think this'll work. Airlines who have the most to gain from a short boarding time (budget airlines) have another approach, where they do not assign seats. Individual passengers are motivated to board quickly because they don't want to be sat next to a big fat person, or they want to stay with their group.

Ryanair has an average turn around time (time between when the plane lands to when it takes off again) of 25 minutes. I've been passed through the gate and waiting at the door before the plane I've to travel on has landed.

ColinWright• 15 years ago

This has been going on for over 2 1/2 years now. At that time we had this item submitted:

http://news.ycombinator.com/item?id=419360

It looks like it's the same physicist, and the same algorithm. Further more, HN had pretty much exactly the same discussion.

Plus ça change, plus c'est la même chose.

There's another submission from over a month ago here:

http://news.ycombinator.com/item?id=2790023

In that it's described how ...

    American Airlines undertook a two-year study to try and
    speed up boarding. The result: The airline has recently
    rolled out a new strategy—randomized boarding.

I haven't seen any news of how that panned out.

This submission from 1300 days ago - http://news.ycombinator.com/item?id=111416 - is a paper from Arxiv, suggesting that boarding times can be cut by a factor of 4. Guess who it's by - yup, our favorite physicist again. So he's been at this for 3.5 years. There are just 5 comments on that submission.

This latest paper is here: http://arxiv.org/abs/1108.5211

That was linked to from this submission: http://news.ycombinator.com/item?id=2943615

It was also referenced in the article pointed to in this submission: http://news.ycombinator.com/item?id=2943003

All in all, a popular topic that's been going for 3.5 years from this one physicist at least.

Despite his perseverance, it hasn't been adopted on any of the flights I've been on.

========

So here's a list of some of the previous HN items on this topic:

http://news.ycombinator.com/item?id=111416

http://news.ycombinator.com/item?id=419360

http://news.ycombinator.com/item?id=924855

http://news.ycombinator.com/item?id=2790023

http://news.ycombinator.com/item?id=2943003

http://news.ycombinator.com/item?id=2943615

notahacker• 15 years ago

Given that he's been studying it for a while, it's received news coverage and airlines have been very keen to find ways of saving money over the past 3.5 years, it probably doesn't work nearly as well in practice...

Faster method of boarding still: don't assign seats within classes.

nvictor• 15 years ago

Sherlock? :O

alttag• 15 years ago

The article makes the assumption (or at least fails to demonstrate) that the bottleneck is boarding, as opposed to deplaning or cleaning. Other processes which may be done in parallel could just as easily be a bottleneck: food, sanitation, gas, luggage, and such.

And with super-fast turn-around times, airlines might have less time for inspections or maintenance, as we've seen with Southwest's recent problems. (Southwest reportedly has the fastest turn-around time in the industry, in part due to their standardized fleet.)

yannis• 15 years ago

It always puzzled me that a simpler algorithm has never been considered.

Passengers with heavier hand luggage or more than one piece (say hand-luggage and laptop) should be given back-seats. Anyone without hand luggage should be placed at the front seats.

sfriedrich• 15 years ago

Shouldn't he have cut it in half and then half again by now. Hopefully we can keep cutting it in half!

Physicist cuts plane boarding time in half

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