

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

======
ColinWright
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
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.

------
zeteo
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).

~~~
city41
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
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.

~~~
vacri
Colour coding the ticket is not trivial - current monochrome printing is easy
with thermals. Ever run a colour printer in an office? It's a nightmare to
manage just in an of itself. Then there's a lot of investement in creating a
system that works across all models of planes. It's doable, but it's not
trivial.

Then on top of that is the issue that despite all this, a lot of people ignore
what's on the tickets anyway and board when they feel like - the boarding crew
are not going to tell someone to go back against the surging crowd and wait
their turn. I've been on four international flights before and I followed the
"people in this block, board now" - and when I entered, pretty much every time
I passed by an uncalled block, it was at least a quarter full. People aren't
disinterested particles.

Given also that planes are sitting around doing things both before and
frequently after passengers have boarded (or waiting for the late
passenger...), I don't think a straight-out claim that 10 minutes shaved off
boarding times is a direct 10 minutes shaved off turnaround times (not that
the article claims this, just being wary of it)

The video shows an "aisle management" technique, but it isn't a "boarding"
technique, as the latter task is much more than wandering down the aisle.

~~~
roel_v
You don't have to print the colors, you can have pre-printed tickets in two
colors and have two printers at the checkin counter (likely much cheaper in
ink, too, and much better-looking).

------
cliff
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
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).

~~~
davvid
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.

~~~
joeyh
I always board last. I'm going to be spending too many hours on the plane
anyway, why would I want to spend yet another hour sitting motionless on the
tarmac when I could be out where there's power and wifi and restrooms? So I
book an aisle seat and ignore the zone calls and get in line near the very
end.

Then I make up for being in some way possibly antisocial by helping someone
with their luggage or something.

(As noted, I don't pay too much attention to it, but I do think they often
board the tailies before the center on at least some airlines.)

~~~
dantheman
The only problem with boarding last is that there may not be any space to
store your baggage, and you'll have to check it.

~~~
vitalysh
You can always ask air hostess to store the luggage in their compartment. Did
that number of times with Lufthansa.

------
martingordon
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.

~~~
madh
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.

------
kemayo
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.

~~~
______
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.

~~~
kemayo
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.

~~~
jbri
Alternatively you could walk in as soon as boarding starts, sit down and start
reading, and not have to worry about looking up every few minutes to see
whether it's your turn to board yet.

~~~
kemayo
That's where the people-walking-by-jostling-me bit comes in as a motivator for
staying out.

Besides, why look up when they're announcing things over the P.A.?

------
jgfoot
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...](http://online.wsj.com/article/SB10001424053111904233404576457930970524522.html)

~~~
jcampbell1
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>

------
matthew-wegner
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
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.

------
rmc
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.

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

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

------
Nate75Sanders
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.

~~~
swhitt
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
You obviously don't have long legs.

------
frossie
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
_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.

------
pyoung
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.

~~~
joshwa
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.

------
stretchwithme
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.

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

------
LiveTheDream
The source paper: <http://arxiv.org/abs/1108.5211>

------
mef
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.

------
psychotik
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.

------
alttag
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.)

------
wooswiff
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?

------
teyc
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.

------
mgkimsal
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.

~~~
joshwa
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.

~~~
mgkimsal
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).

------
synacksynack
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...](http://leeds-
faculty.colorado.edu/vandenbr/projects/boarding/boarding.htm)

------
Bud
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.

------
SonicSoul
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..

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

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

------
yannis
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.

------
arturadib
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.

~~~
lojack
> 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
Adding boarding doors costs money too.

