
London’s Legendary Taxi-Driver Test Puts Up a Fight in the Age of GPS - jaynos
http://tmagazine.blogs.nytimes.com//2014/11/10/london-taxi-test-knowledge/
======
jes5199
GPS routing is awful compared to a person who knows their way around a city.

Uber drivers in hilly cities like San Francisco never, ever think to avoid
climbing right up and down the steepest hills - the algorithms don't tell them
not to, there's no _traffic_ and it's not a low _speed limit_ , it just sucks
for other reasons.

I had a driver last week who had never heard of Valencia St, and then
misunderstood the GPS voice and accidently got on the freeway, getting us
stuck in cross-bay traffic for 20 minutes just trying to get to the next exit.
Of course I rated that ride 5 stars, because I'm not actually a psychopath (
[http://www.forbes.com/sites/jeffbercovici/2014/08/14/what-
ar...](http://www.forbes.com/sites/jeffbercovici/2014/08/14/what-are-we-
actually-rating-when-we-rate-other-people/) )

It's going to be a long, long time before we put anything approaching the
depth of information that years of experience brings into our algorithmic
routing systems. And startups are structurally disincentivized from trying to,
anyway.

~~~
ntoshev
It is a trivial problem. Track how anyone with a smartphone and your app on it
moves around the city. Aggregate which paths they choose and which turn out to
be faster / better. Then propose those paths to other users asking for routing
instructions.

I work on a software for routing deliveries
([https://www.fleetnavi.com](https://www.fleetnavi.com)), and although we
don't have this functionality built into the platform yet, it's the first
thing to do when we get volume.

~~~
crazypyro
Tracking, aggregating and analyzing thousands of users with slightly varied
destinations, focuses (less traffic, faster, scenic), and signals is not
exactly what I'd consider trivial...

~~~
custardcream
It's not a terribly hard job actually. I worked for a startup in 2004 that was
doing this with haulage companies. We had 8000 data points moving around the
UK coming in via GPRS and 3rd parties, traffic information aggregated and
routing and mapping data, pick up corridors and event data.

It was (bar the web front end) a relatively modest sub-30kloc chunk of C++.

Now the scale is different but in 10 years, the problem isn't necessarily much
more complicated, just larger.

In fact I think a derivative of it now runs some of Yodel's operations.

~~~
mattmanser
30kloc is not a trivial problem, that's a year's worth of programming.

I also love this:

 _the problem isn 't necessarily much more complicated, just larger_

If a programmer ever said this to me, it'd be a massive red flag that the
estimate they're about to give me is going to be very wrong.

~~~
Retric
It's a larger data-set not a more complex problem.

Also, there is no need to get a perfect solution anything better than what's
out there is useful.

~~~
stevenbedrick
> It's a larger data-set not a more complex problem.

Ummmm... yeah, scaling the kinds of algorithms that one might apply to this
sort of problem up to larger data sets is often extremely difficult.

------
goatforce5
Several times I had London cabbies stop the fare meter when I showed them (the
same) short cut near where I lived.

"No, don't go to the lights, turn down this lane!". All of them had their
brains explode that there was a better way that saved about 200 meters and 30
seconds of travel.

I'm not sure if there's an (unwritten?) rule that you get the rest of the fare
for free if they're taking you a long way, but there was no resentment from
them. All of them were incredulous there was a better way to do it.

(Just looked at Streetview. There's nothing special about that lane that
should make it a big secret. I guess it must have been No Entry/One
Way/something and changed recently before my journeys.)

~~~
justincormack
It is honour. Have had free trips because they didn't know a street in eg
Swiss Cottage. It encourages repeat business.

~~~
peteretep
25% of cab drivers had no clue where Gaskin St was, and I never had any
suggest they were going to knock off the fare in three years...

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rbobby
The "knowledge" is a very valuable skill/infoset. The actual driving and
interacting with customers is much less valuable. So maybe the way forward is
to separate the two skills.

Folks with the "knowledge" could act as centralized route planners. The can
provide many more routes in the time they could drive one (i.e. a single cabby
driving might do 1 call every 20 minutes... but could easily do 10 route plans
in the same time).

Essentially when someone asks the minicab driver "take me to X", the driver
relays this information to a black cab driver at a desk who sends back a
custom route. With GPS to identify the starting point and VOIP (via wireless)
this could be as easy as a driver using a traditional radio (press the mike
button, speak the destination, and viola the route appears on a dash mounted
map along with spoken instructions).

Very much like the existing examination question/answer format.

Maybe you would also need to rotate the route planners out as drivers 1 week
out of 4 so they keep up with the "knowledge".

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mtalantikite
Here in Brooklyn car services seem to have lost the ability to navigate the
city in just a few years. You used to be able to call a car service, have a
car show up in 5 minutes, and they'd get there with just the cross streets.

Now most often the first question is "what's the address so I can put it into
my GPS", even with metered cabs. I've been yelled at for asking to take routes
that the GPS doesn't suggest, even though I know at 3pm on a Tuesday we
shouldn't be on the BQE. Or there's construction on Flatbush and we should go
around it.

I don't think we need a test quite like London's, but basic knowledge of
neighborhoods and major intersections should be required. At least until we
get those self driving cars that can optimize routes in real time.

~~~
danielweber
My (limited) experience in Brooklyn is that taxis don't know addresses, they
know cross-streets.

~~~
mtalantikite
Yes, that's generally true with all of NYC, we always give cross streets as
reference. I'd never expect anyone to know just based on address number.

------
macieka
Even though in London black cabs are significantly more expensive than uber x,
they are a much better experience. I often order an Uber in the pretty busy
area of Soho, only to stare at the app for 10 minutes as my driver turns into
dead end streets time and time again trying to get to my location. I don't
really understand why this is happening, because they usually have both a
separate GPS and the uber app that should display driving directions.

Black cab drivers know so much more about the city it's not even a contest. I
have almost totally switched to using Hailo in London for that reason.

------
IvyMike
Reading the article, I can't help but think that a GTA/CrazyTaxi street-
accurate video game based on this test would be amazing.

~~~
balabaster
You could probably sell it to the Knowledge Boys & Girls cramming for the test
- they wouldn't have to log so many hours on the road putting wear & tear on
their rented vehicles trying to cram for the test. They can run around for as
long as they can stay awake without ever leaving the comfort of their home.
Plug it into something like Occulus rift or some VR environment... and if they
hit traffic, they can kill that mission and start again, finding a better
route instead of in being stuck in the very tiresome reality of sitting in
traffic for 40 minutes by taking a wrong turn.

~~~
solistice
The main problem I see with that is detail and the age of your data.

Drawing from experience trying to memorize a journey through the city of Bale,
which whilst less large than London is quite winding and certainly suffers
from the same compounding of historical and modern buildings. Going through my
route, spots where i stopped to take in more details are very much more
tangible in my mind. The wide park circled by a walkway where I stopped for a
short break is quite vivid in my memory, and I can pull dozens and dozens of
points from it. The path along the viaduktstraße leading up to it is far more
faint in my memory, considering I only remember the Paulskirche and one of the
bridges towards it. Considering only something akin to Google Streetview would
be practical, there seems to be just to few points your mind can latch onto to
create a detailed image of the location. In addition to that, your other
senses do play a significant role in remembering locations.

Also, cab drivers need to know very recent information you're tempted to
overlook designing a game like that. How fast does traffic go at this time of
day at this location? Are they setting up construction over here? It's often
not even realized consciously, but rather factors into decisions on a lower
level, turning into the "hunch" you have about a certain route or even more
generally a certain course of action.

So unless there is a way to have a perfect representation of the city that is
also less than a day or two old, it's not really a replacement for actually
going through those streets.

~~~
gknoy
Does the test check the best way, or only knowledge of finding Some route? I
could see someone learning the city topology with VR, and then using
experience to learn congestion patterns.

------
bmsleight
Check out the run calling halfway down the article (Matt McCabe “calls-over” a
long run)

~~~
blahedo
Yes, and notice how much of the run involves "forward" calls---that's when you
stay on the same road, but it changes name. It's mindblowing.

If you want to track the run (it's accurate!) the starting point is right next
to this node in OSM:
[http://www.openstreetmap.org/node/279219489](http://www.openstreetmap.org/node/279219489)

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igonvalue
I thought the coolest fact about the Knowledge is that it actually induces
observable physical changes in brain anatomy.

> She has discovered that the posterior hippocampus, the area of the brain
> known to be important for memory, is bigger in London taxi drivers than in
> most people, and that a successful Knowledge candidate’s posterior
> hippocampus enlarges as he progresses through the test.

It seems that, like most things, there might be a tradeoff involved. According
to this paper[0],

> However, they were significantly worse at forming and retaining new
> associations involving visual information. We consider possible reasons for
> this decreased performance including the reduced grey matter volume in the
> anterior hippocampus of taxi drivers...

[0]
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2670971/](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2670971/)

------
conorh
I would take a London taxi for the same reason that I'd read a paper book, for
the experience, not for the result. The Knowledge is such a wonderful
anachronism, and I hope that it can co-exist in some form with new services
such as Uber and Lyft, but outside of protectionism I can't see any reason why
it should - technology is nearly good enough now to replace it, and in some
cases probably better. If it does continue to exist I can't imagine that
market for people with the Knowledge will be enough to support the number of
London taxi's that are on the streets now.

~~~
gutnor
Most of the black cab I have taken have a also a GPS, so that's not like it is
an exclusive type choice, and I wonder why people assume so. Even connected
GPS are fairly bad at finding the shortest way if it means running in the
other direction for a while and that happens quite often in London and Black
Cab driver are quite good at making those kind of info just looking at their
gps traffic info.

The knowledge is a very useful tool, and in any city, a driver with good local
knowledge is what you are looking for, regardless the middleman you use.
Technology is only making the trade off of using amateur bearable, and in
reality the real value of Uber and others is from the rest of the service
provided.

A bit like in your example - if you had to go to the bookstore to load a new
book on your reader and it could only hold one book at a time, the
technological superiority of even the latest generation of kindle would not
make them go pass novelty items. Real value of ebook comes from the rest of
the services you get from it and that's the reason why even with the shit
reading experience, the first gen kindle was a success.

The anachronism here is the segregation between black cab and minicab in
London and the services the legal restrictions on the services they can offer.
Although, IMO, that is not nearly as bad in London as people on HN experience
in other places in the world. Black cab are meant to hailed on the street,
now, without booking, review or other overhead by drunk people and tourists.
Some licensing restriction to make sure you get a basic level of service in
those circumstances is probably acceptable. If you have time to plan a bit in
advance, there is Uber and plenty of competitors that have always been freed
from the restrictions.

------
nwp90
A lot of people seem to miss the point that the Knowledge also acts as a
deterrent to bad behaviour by proper cabbies - they have too much invested in
their license to be likely to throw it away lightly.

~~~
rahimnathwani
It's not about how much they have invested; this is a sunk cost. One cannot
change the past. It's about the future revenue they would forego if they were
to lose their licence.

------
jively
London Black cabs are overpriced, and there's no market check that stabilises
price, as much as I respect the institution of "The Knowledge", you are still
bound by the need to trust your driver, and many are just opportunistic.

The Knowledge may make for better navigation, but as a customer, the amount of
times it actually comes in useful (road works, accident, awkward route) is
very low, 90% of journeys are straightforward.

It certainly doesn't justify the 50%-100% price increase for the privilege of
hailing the cab on the street vs. by pre-booking, especially when most of the
time the route you are taking is short (no Londoner in their right mind would
use a black cab for a long journey, unless they have money to squander or it's
so late at night that you're desperate)

The likelihood of getting any real value out of the knowledge when taking a
cab in London is very low, and the fact I need to pay for idling in traffic
with an un-capped fare potential on top of jacked rates just makes for a
terrible proposition.

As a consumer, there's just no value in that, and Black Cabs need to evolve or
compete themselves back into relevance, bring on Uber, Lyft, Wheel and any
other newcomers.

Source: 14 years of being a grumpy Londoner.

------
Evolved
I'm a fan of the 3 yes/no question survey. It doesn't take much longer than
rating 1-5 unless you want to add comments.

Would you use our service again?

Was there anything we could have done better? (+comment)

Would you recommend us to your friends and family?

Also, let's not forget how _people_ sometimes lose their ability to be
objective when they're upset which may manifest itself in the form of a less
than 5 star rating for a driver that made 1 small error or said something
innocuous that we took offense to.

------
solistice
Having lived for some time in Beijing, where a "black cab" is a slang term for
an unmetered private cab or metered cabs running with the meter off, reading
the part of the article detailing "black cab advocacy" and "black cab
protests" turned into more of a mental challenge than I would like to admit.

------
chuckcode
As automatics routing software takes into account the extra information of
traffic history with real time existing traffic conditions computers will do
just as well or better than "The Knowledge Boys". Currently local experience
with traffic is very useful, but as that information becomes available
electronically and much more comprehensively the playing field will tilt even
more to automated analysis. UPS already uses their combined driving history to
save millions of man hours and millions of tanks of gas[1]. I have to imagine
that Google and others can do even better with all of us implicitly telling
routes and existing traffic conditions. Be interesting to know if Google is
doing a/b testing with their routes in maps like they do with their website
UI.

[1] [http://www.bloomberg.com/news/2013-10-30/ups-uses-big-
data-t...](http://www.bloomberg.com/news/2013-10-30/ups-uses-big-data-to-make-
routes-more-efficient-save-gas.html)

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dkopi
Infamous would be a much better description than legendary.

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piyush_soni
I wouldn't be surprised if they gradually start losing cab drivers.

