
The Huge, Unseen Operation Behind the Accuracy of Google Maps - dreamweapon
http://www.wired.com/2014/12/google-maps-ground-truth
======
erjiang
If you're fascinated by maps and digital cartography and haven't done so yet,
do check out OpenStreetMap! It's competitive to Bing, HERE, etc. but
everything is open, and the data is yours to play with.

There are projects based on OSM for routing, geo search, map editing, etc.
that are also free. Definitely a lot of room for both programmers and non-
programmers to contribute.

[http://wiki.openstreetmap.org/wiki/Main_Page](http://wiki.openstreetmap.org/wiki/Main_Page)

~~~
MCRed
I've had a great experience with Apple Maps, which are based in part on Open
Street Map (giving data back too) and TomTom. I've found it's accurate enough
to just trust it, and it's excellent at detecting and rerouting when I can't
do what it wanted me to (eg: traffic in the way, or I just miss the turn.)

~~~
discardorama
Outside the US, Apple Maps suck ass (I'm sorry, but there's no other way to
put it).

~~~
threeseed
It depends on the city. In Melbourne, Australia for example I find Google Maps
to be less accurate than Apple Maps. I also found the same in parts of Tokyo.

------
mempko
This is a very detailed article. Most people do not appreciate how much work
is put into building these digital maps, so it is great to see these kinds of
articles.

While not as detailed, for contrast I want to post how Nokia's HERE maps
builds their maps.

[http://360.here.com/2014/11/17/made-usa-people-fargo-make-
ma...](http://360.here.com/2014/11/17/made-usa-people-fargo-make-maps/)

That is from the company blog. It shows a couple of our tools, but not nearly
all. I work for HERE maps and my opinion is my own.

I just thought that people might be interested in how other companies like
HERE build maps. Despite all the automation (at both google and HERE), it is
still a human intensive process and there are people on the other end making
it as correct as can be. Also, I can't go beyond what is written on the public
blog as I am not a company spokesperson.

~~~
bostonpete
I can't imagine the amount of ambiguity that comes up in every day
conversation when the name of your project/division is "here". Do you have
internal language that's used to avoid such ambiguity?

~~~
mankyd
I used to work for a company called "Going". We had no alternative internal
code name. (I swear, if I heard one more pun about where I was "going"...)

That being said, you'd be surprised how little you need to refer to your own
company by name internally, especially in an ambiguous manner. Usually its
just "Hey, can you put this up on the site?" or "It would be cool if the
product did X."

------
Someone1234
Google Map's data keeps getting better and better, they now have lane warnings
(e.g. "right two lanes," etc) and traffic warnings with the offering to re-
route (if they can find a quicker route). Although Google Map constantly
offering to re-route me onto a slower route is a little odd (e.g. "want to re-
route? It will be a 5 minute longer trip!").

That all being said, while Google Maps as a data source is amazing, Google
Maps as an app and or web-site has a lot to be desired. Up until a few
versions ago they had a way to add "My Places" but no way to actually access
those places from the app (what?!). They have no search history (still,
today), they do have suggestions but they are just somewhat useful, they have
no compass (got removed), plus they went all "minimalist" and hide all the UI
elements (and removed things like offline maps, for nearly a year).

I've actually been forced to stop using Google Maps as GPS as the app keeps
closing during navigation and when re-opened it has "forgotten" what I was
navigating to or previously searched for. So now I am forced, mid-journey to
exit the freeway just to re-open Google Maps, re-search for my destination,
and then re-start navigation just hoping it won't re-close-randomly before I
get there...

It doesn't crash. It just closes. It is just gone. Like "poof." Then of course
the phone goes into standby as nothing is keeping the screen on. At least if
it had search history the situation MIGHT be recoverable, but nope...

~~~
psaintla
I agree completely, there are so many great features I think they could have
added instead of changing the interface.

1.) Send directions to a mobile device. There are many times where I search
for directions or map out an alternate route on my desktop. The only way I can
access those directions is to email it to myself then open the email on the
mobile device. Why not just store the data and let the user retrieve it on
their mobile device?

2.) Better accuracy of property in rural/suburban areas. It's odd to say this
but Bing Maps is actually much more accurate in rural areas.

3.) More fine grained control over street view placement.

4.) Offline maps! Not everywhere has good cell coverage.

~~~
Someone1234
> Send directions to a mobile device.

Yeah. How is this not a thing?! I imagine a lot of people search for things on
their desktop and then want to "push" it to their phone for navigation, but
yet I have to re-enter the zip into the phone to do so.

~~~
commandar
I tend to get Google Now notifications for directions I've searched for on my
desktop.

~~~
psaintla
That is really intermittent for me. When I first started using Google now, I
got them. These days, it only shows destinations I frequently travel to.

------
civilian
I worked as a contractor in Kirkland on this project for about a year.

Just for context, the first image with the red and green dots--- each dot
represents a 360-degree "street view" image. While consumers only get half-a-
dozen a block, the operators got access to all of them. (Green are HD, red are
normal def.) It was really useful for verifying that businesses had closed
because the streetview dots also had the exact time that they were taken.

There was also deeplinking in Atlas to a specific dot and direction vector. So
when I was submitting a change to a business, I could link to the exact sign
that I saw to prove that "Mama's Teriyaki is on _that_ corner", which helped
whoever QA'd my change.

It was a great first job out of college given that my degree wasn't very
relevant to anything. (A lot of my coworkers in the same spot--- young, a
degree that wasn't too useful, trying to find anything to do.) Out of the 400
contractors in that first Kirkland "class", I see tons of them around the
Seattle tech industry now. It's been a surprisingly good network to have.

At the end of the day it was still data-entry / data-validation, and mind-
numbingly boring.

~~~
ghshephard
This is actually very fascinating. About how many businesses a day would an
average person versus a prolific or slow person manage to update? Did you
mostly work off of business signs to determine information about businesses?
What if no recent pictures had been taken?

~~~
civilian
We'd also use the internet and, reluctantly, call them. We would identify
ourselves as google maps, calling for info about their business.

I don't quite remember the numbers, but it was something like 40 a day? The
slower and new peeps would be around 25, and the fast people could do like 80
a day. But there weren't any productivity bonuses besides not being let go, so
me and my buddies would do about 10% more than the average and then goof off
on the internet or do homework for our python night class.

------
TazeTSchnitzel
It's wonderful what Google are doing with Google Maps, but I can't help but
wish these maps were open to use by their competitors.

Imagine a world where all the effort Google, Apple, Microsoft and Nokia put
into their maps all went into OpenStreetMap instead.

~~~
cylinder
Can't understand the reasoning behind expecting a company to pour hundreds of
millions of dollars and resources into something for free / no return at all.

~~~
ZeroGravitas
Because once you get the incentives correctly aligned it's a massive boost in
global wealth?

~~~
zo1
It's easy to talk about "boosting global wealth" when it's other peoples'
money.

~~~
rictic
The parent and great-grandparent haven't proposed seizing private property,
they're just noticing and drawing attention to waste. The observation is that
if we could align incentives such that Bing, Google, OSM, Apple, etc were all
investing aggressively into the same map data then everyone would be better
off.

Maybe we can't! Capitalism is pretty damn good at some problems, optimal even.
But it's not flawless, and it is worth noticing and thinking about places
where gains appear to be possible.

------
koenigdavidmj
Their screen capture of the Seattle Center area is particularly amusing given
that their competitor Apple Maps still hasn't figured out:

1\. That Broad St no longer exists for a significant portion of its length.

2\. That Mercer St has been two-way for months now.

This is _the_ major east-west road in that area, and they can't even get that
right.

Yes, I've reported it regularly for months now.

~~~
beering
I think Apple gets the short end of the stick in these deals. The company that
provides that mapping data usually has ridiculous restrictions on what you
can/can't do to the data (even possibly disallowing your own patches), and
Apple takes all the heat from users.

~~~
notatoad
Apple has their name on the product, it's their responsibility to ensure it is
up to par. It doesn't really matter who the fault lies with, if the data
coming in isn't good enough then apple should be looking for different data
sources.

------
ChuckMcM
They started Ground Truth when I was there and it really opened my eyes to
just how "broken" a lot of map data sources were at the time. Something I
considered to be a 'solved' problem (take aerial photograph, pull out streets,
poof map!) was no where close to solved.

Some folks have said that Ingress, the Android and now iOS, real world geo
game. Was in part an exercise in data collecting. Get people to photograph
land marks in the real world to make "portals" while collecting GPS data
associated with public landmarks for maps. And then use that data to localize
things in satellite imagery, etc.

Makes for an interesting data set.

------
spinchange
It's little wonder that Google Maps is such an amazing application given all
the time, intelligence, resources and just the sheer commitment Google's shown
to it.

I know business considerations are what they are and often independent from
others, but nothing shook my belief in Apple's commitment to quality as a
defining principle more than the decision to replace Google Maps with Apple's
own half-baked beta offering. Does anyone think they'll ever give maps &
cartography the kind of attention to detail that Google's given it?

~~~
visarga
> Google Maps is such an amazing application

Not so amazing. Just the data is amazing. The app sucks.

~~~
brandonwamboldt
The app may not be great, but it's pretty good, especially for the vast
majority of users. From Google's perspective, I doubt it makes sense to add
features that many of their users don't need and won't use.

~~~
visarga
I only need the "feature" that when it crashes, it should remember the route
so as not to have to use (often missing) data connection in the middle of the
trip. It's such a simple concept - save all routes for later recall, even if
offline.

------
sytelus
Another similar article appeared two years ago:

How Google Builds Its Maps—and What It Means for the Future of Everything

[http://www.theatlantic.com/technology/archive/2012/09/how-
go...](http://www.theatlantic.com/technology/archive/2012/09/how-google-
builds-its-maps-and-what-it-means-for-the-future-of-everything/261913/)

I think most interesting point is not covered in either of them: How much of
this effort devoted towards human curation? The numbers are believed to be
~1100 full time employees and 6000 contract workers[1]. These are huge numbers
compared to most competitors in the market. Assuming each correction to a map
can take 15 mins on average, you can easily make 100,000 corrections a day.
Again, assuming there are top 2000 cities in the world where most of the
queries originates, this is about 100 corrections per city per day. This would
guarantee Google maps best of the best freshness, precision and recall on most
metrics. With about 10X-20X larger curation force plus algo engineering, likes
of Apple or HERE have no chance. In a way this also shows Google's leadership
wisdom. Maps are _the_ most important thing on mobile and even on web. Most
companies don't get this and provide minuscule budgets citing no potential
revenues (for instance Ballmer cancelled Street View like effort at
Microsoft). By the time they wake - if they wake up - it would be to only find
that they have been outrun by such a huge gap that even a decade won't be
enough to catch up.

[1] [http://www.businessinsider.com/to-do-what-google-does-in-
map...](http://www.businessinsider.com/to-do-what-google-does-in-maps-apple-
would-have-to-hire-7000-people-2012-6)

------
plg
difficult to imagine why apple would have even attempted to get into this
space ... they must realize they can only be a second rate player. maybe
that's good enough for them? doesn't fit with their story/ethos though

~~~
stephenr
Why do you assume an advertising company is better equipped/able than a
technology company to run a maps/routing service?

~~~
spinchange
Setting aside how one views/classifies the companies, you don't have to assume
anything: Google's maps have qualitatively better data than Apple's because
they've literally been driving & photographing much of the world's roadways.
Apple shows no indication of having this kind of commitment and even if they
did, Google has a significant, years-ahead lead.

~~~
stephenr
So your theory is that Google must have better data about what is in a
specific place, and how to get there from somewhere else, because they have a
photo of that place, from the street?

~~~
spinchange
Well, according the featured article we're commenting on, yes, that's about
half of it in a nutshell. The other half is the algorithms they're running on
all this street view data they're collecting.

Is it really that crazy a notion that actually driving the roads and
collecting all kinds of data from it yields higher accuracy maps than just
licensing less robust data sets from others?

~~~
stephenr
trying to reverse engineer a photo of a property from the street into
meaningful information, vs using data collected from businesses dedicated to
providing mapping/location data, and information provided by people expressly
interested in improving the available data?

Sure, keep analysing that shop front.

~~~
spinchange
Look, obviously there's more to it than _just_ street view and algorithms. The
article also talks about manual reviews, corrections, and verifications by
lots of human staff. Google also allows businesses to add/update their
listings. I've done it for ours. I've then had someone from Google call me to
confirm it too. They also have Skybox imaging now as well as Waze.

I focus on street view because it is a big source of data (per the FA) and a
testament to the comitmment and effort that's gone into it. In the U.S., how
many other map makers actually drove 99% of the roads on thier map? Maybe that
doesn't make a difference to you, but I think the central premise of this
article and the general consensus of most users is that it does.

------
shutupalready
St. Louis streetwalker serial killer, Maury Travis, sent the local newspaper a
computer generated map giving the intersection where he left a body.

Investigators determined that web-based mapping software Expedia was used--
based on symbols used to mark highways and such--ruling out Mapquest, Yahoo,
and others.

A single person had clicked on that intersection in Expedia in the 5 days
before the map was received by the newspaper. They traced the person
presumably using the IP address.

This was back in 2001.

It's odd that we still have unsolved street crime given that everyone today
carries a tracking device sending back real-time geolocation data.

------
efalcao
There was a great talk on this at Google I/O 2013. Recording here:
[https://www.youtube.com/watch?v=FsbLEtS0uls](https://www.youtube.com/watch?v=FsbLEtS0uls)

------
calinet6
I dunno, there's been a Starbucks open a couple blocks from me for six months
now. Wasn't on Google Maps until I went and added it myself!

~~~
beering
It's incredible how Google can get so many people to work for them for no pay.
Would you similarly contribute to closed-source proprietary software if given
the opportunity?

~~~
zaphoyd
I'd put that sort of contribution in the detailed bug report category,
something I'd absolutely contribute to closed source proprietary software if I
thought there was a good chance it would get fixed and that I wouldn't have to
deal with it being broken anymore.

------
rickdale
Google maps is amazing. I was on my way to Detroit Airport, I live about
1.5hours away. Anyways, I wanted to double check directions so I used google
maps, and it came up with directions that were going to take me 2 hours. I
laughed thinking, 'oh technology, 2 steps forward, 1 step back'. So I drove
down the way I already knew and was just double checking. With twenty minutes
left in the drive, theres a deadstop traffic jam. Highway is closed. Turns out
entire highways flooded in Detroit around 6-7am, and when I googled directions
around 830am, google knew not to go that way, but I didn't. Made it to the
airport 3 hours later, with a flight 6 hours after that. I had never been so
impressed with google maps before this though. How did it know not to go that
way so fast? I literally just drove right into it no warning or detour signs.

~~~
bhousel
They have gotten really good at this since acquiring Waze, which crowdsources
traffic data.

------
jedberg
And yet, when I want to go from SFO to Cupertino, it absolutely refuses to
offer taking 380 to 280, even when it is 10 to 15 minutes faster according to
Google itself.

Apparently they still haven't fixed the whole "we have to go directly away
from the destination for a little while" problem.

------
matt_kantor
> The majority of buildings in the U.S. are now on Google Maps.

I doubt this. Out of curiosity I looked at my family's farm and Google Maps is
missing most of our outbuildings. More generally I'm sure that they come up
short on backyard sheds, pool buildings, structures in dense forests, etc.

~~~
jameshart
Where do you think _the majority_ of buildings are? I mean, there's a long
tail, but more than 80% of the US population lives in urban environments; the
head of that density graph is _massive_.

------
juliendorra
An interesting anecdote: the "promenade claude lévi-strauss" is a new street
in Paris (around 1 year old, pedestrian only). It doesn't exist in Google Maps
yet, which make Uber fail when you try to go there as Uber rely on google
maps. (many people might want to go there, as it is now where all the paris
urban planning administration is. I had to for a permit.)

Actually last I tried Uber/Google Maps sent you at the directly opposite
corner of Paris, to the Quai Branly Museum, probably because there is
something related to the anthropologist there (?).

Both Apple Maps and more interestingly the crowd sourced OpenStreetMap know
about the "promenade". I'm curious to see how long it will take Google to
discover this new street.

~~~
rmc
> _more interestingly the crowd sourced OpenStreetMap know about the
> "promenade"._

Not too suprising really. OSM can be updated in a minute to add new features.

------
lingoberry
After relying on Google Maps a lot for many years living in the US, I have
(maybe unsurprisingly) noticed that it doesn't work nearly as well in Europe.
As in, I'd zoom in on central Stockholm and search for something common, like
the name of a restaurant, and Maps would promptly swoosh me to Nicaragua where
it found a place with that name. It's doing stuff like this so often that I
rarely use it anymore.

------
amoshag
This article shows that Waze's method of crowd sourcing maps is the right way
to go. Waze is able to have realtime detailed information about every street,
building, directions, etc. including all the details that were discussed in
the article + much more (e.g. future road changes), and most importantly it
does that in a fraction of the cost. Now it seems that the 1.3B that Google
paid for it is probably a bargain

------
cjensen
Despite all of Google' effort, they still rely too much on USGS published
maps. For example, just 6 miles from the GooglePlex is a road in Newark with a
gate [1], but Google doesn't know you can't drive on it.

They're doing a good thing, but unless you can see that Google has driven the
route and has published street view, you can't entirely trust them.

[1] 37.515696 -122.050873

------
danellis
So they have speed limit information? It would be handy if you could have that
information on the navigation screen, maybe even with a warning when you
exceed it.

------
forrestthewoods
I'm still waiting for smartphones to be more fully crowd sourced into maps. I
badly want real-time traffic data to come from smartphones.

~~~
beering
This already happens on Google Maps. Or do you mean in an open-data way?

~~~
forrestthewoods
Is the data gathered from crowdsourced smartphones? If it is then the
precision is shit. Waze has been continuously unimpressive in dense urban
environments. It can sometimes take 15 minutes to go two blocks through two
lights. And neither Waze nor Google Maps correctly show that.

Using the GPS drains battery and there are huge privacy concerns. It's not an
easy thing to do right. But I think it can be done.

~~~
wmeredith
>>Is the data gathered from crowdsourced smartphones?

Yes. Google deduces traffic congestion by the speed of Android devices in
cars.

------
th0ma5
Anyone have resources for mitigating the web map zoom level inaccuracy bug? I
guess I know this only as the OSM bug, but it is the reason web mapping like
OSM and Google Maps isn't used much by true GIS analysis. You can see this
most easily by having your GPS on with your phone and using Google Maps on the
web. When you zoom out your location accuracy decreases the more zoomed out
you are. This doesn't seem to happen on the Maps app on my phone.

~~~
aw3c2
What are you talking about?

~~~
th0ma5
[http://wiki.openstreetmap.org/wiki/Osmarender_bug](http://wiki.openstreetmap.org/wiki/Osmarender_bug)

~~~
rmc
Osmarender hasn't been used in years. A new and faster tile service on the
main openstreetmap.org website was deployed and that makes osmarender
unneeded. Try OSM now, it might be good for you.

~~~
th0ma5
So the problems this article brings up about the Google Mercator projection
have been solved? Do you have any links to more readings about the issues?

>"We have reviewed the coordinate reference system used by Microsoft, Google,
etc. and believe that it is technically flawed. We will not devalue the EPSG
dataset by including such inappropriate geodesy and cartography."

~~~
rmc
You can render OSM data with any projection you want. Internally OSM stores
lat/longs.

~~~
th0ma5
Well if I still use the Web Mercator I'm still going to have widely inaccurate
feature rendering between zoom levels. Thank you for trying, I guess I should
be asking these questions in GIS forums instead.

~~~
maxerickson
The problems with Web Mercator and spatial analysis are due to the way the
projected data is distorted:

[http://blogs.esri.com/esri/arcgis/2010/03/05/measuring-
dista...](http://blogs.esri.com/esri/arcgis/2010/03/05/measuring-distances-
and-areas-when-your-map-uses-the-mercator-projection/)

The zoom level bug you are hung up on was due to the way web mercator was
implemented in _Osmarender_. This is why people are answering your concerns
about teh zooming by pointing out osmarender is no longer used.

So no, don't use web mercator for analysis. But only worry about inconsistent
rendering across zoom levels if you are using Osmarender.

~~~
th0ma5
Thank you!! Yeah I've never used OSM render, it is just the only place I had
been able to find discussion about the inaccuracies of the projection. It also
exists in all online slippy maps I've used from the latest OpenLayers to the
latest Google Maps. Thanks again!

~~~
rmc
There is lots of discussion about various map projections. There's even a XKCD
strip about it. [http://xkcd.com/977/](http://xkcd.com/977/)

~~~
th0ma5
Thank you, however that is not related to the issues I'm discussing.

