[Talk-GB] UK Project of the week - trace a village off of OSSV?, (Kai Krueger)

Peter Miller peter.miller at itoworld.com
Mon Jun 7 08:26:56 BST 2010

On 6 Jun 2010, at 22:31, Matt Amos wrote:

> +1... or -1 as well? not sure how the arithmetic of these is supposed
> to work. anyway, i agree with phil.
> cheers,
> matt
> On Sun, Jun 6, 2010 at 10:13 PM, Phil James  
> <peerjay56 at googlemail.com> wrote:
>> At risk of being a fly in the ointment, judging by the largely
>> favourable responses to this idea, I for one would like to register
>> myself as
>> -1.
>> <Rant> Please don't map an area if you are not familiar with it. I  
>> have
>> done some armchair mapping, but only where I am familiar with the  
>> area,
>> and feel I can add value to the data I am entering. If you are that
>> desperate for a 'complete' map, go out and do more surveying, or just
>> use OS or other commercially available products.  I just feel that
>> blatant, blind copying of OS data is prostituting what I thought Open
>> Street Map was meant to be about.</Rant>
>> OK, I've got my tin hat on: standing by for incoming... ;-)

My strategy is to pick on an area (the four more easterly Suffolk  
districts initially in my case) and first ensure that all the roads  
from OS Streetview and OS Locator are included by tracing (I am a good  
way through that work now). When I have all of the OS road data into  
OSM I will then promote it within the local papers, both to let people  
know that it is there and to encourage people to use it, but also to  
encourage people to fill in the details.  I will then fill in the  
pedestrian and cycling routes for individual places opportunistically  
when I get the chance to visit the place with a cycle and will be able  
to add this additional data in a single trip.

Personally I think we will get a much better and more complete map  
faster by using all available resources; when people start using it  
then their will be increasing interest in fixing any omissions.

So.. I think my recommendation is 'stick to your local area but  
greatly increase your definition of what is local to encompass at  
least one district or borough, and yes, do use the OS data that is  
available and then supplement it with the odd day-out to fill in more  
detail'. When you have completed your local districts then consider  
adopting a further one but preferably one that you know to some extent.

As a company, ITO is very keen indeed to get full UK coverage of the  
road, pedestrian, cycle networks and schools etc into OSM, in  
particular for urban areas. We will be producing more tools over the  
coming weeks to help identify the level of completeness for different  
places, trends in completeness and others to help increase completeness.


Peter Miller

>> Phil.
>> talk-gb-request at openstreetmap.org wrote:
>>> ----------------------------------------------------------------------
>>> Message: 1
>>> Date: Sun, 06 Jun 2010 12:07:33 +0100
>>> From: Kai Krueger <kakrueger at gmail.com>
>>> Subject: [Talk-GB] UK Project of the week - trace a village off of
>>>       OSSV?
>>> To: 'talk-gb' <talk-gb at openstreetmap.org>
>>> Message-ID: <4C0B8175.30608 at gmail.com>
>>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>> Hello everyone,
>>> I would like to suggest as a sort of "Project of the week" for the  
>>> UK
>>> for people to pick a random town or village somewhere in the UK  
>>> that so
>>> far has poor coverage and trace it's roads from OS OpenData  
>>> StreetView.
>>> Despite the various claims over the years that the UK road will be  
>>> "road
>>> complete" by the "end of the year", the UK is still a far distance  
>>> off
>>> of that target. I have heard the numbers that so far we have on the
>>> order of 50% of named roads (people who are working on OS - OSM
>>> comparisons please correct me if I am wrong). Which is by no means a
>>> small feat of achieving, but also not as high as one would like it  
>>> to be.
>>> So let us try and accelerate this a bit by everyone picking a small
>>> random town or village somewhere in the UK and trace the roads from
>>> StreetView. It probably only takes about 10 - 20 minutes for a small
>>> village and even a small town isn't too bad to do (if the weather  
>>> is bad
>>> and you can't go out). So with the help of OS data, we can get a big
>>> step closer to where we would like to be and use it as a basis to
>>> continue to improve beyond the quality of OS data or any other
>>> commercial map provider.
>>> (If you are convinced already, then no need to read the rest of  
>>> the email)
>>> I know that many people are opposed to "armchair mapping" or imports
>>> (and btw I am not proposing a full scale import here, but manual  
>>> tracing
>>> instead) and so I'd like to counter some of the arguments most  
>>> likely
>>> going to  be brought up against this sort of non local tracing:
>>> 1) OS data might have mistakes, be outdated and generally not as  
>>> good as
>>> what OSM aims for: Yes, no doubt OS has errors and can be outdated  
>>> in
>>> many places by a couple of years ( I have found more than enough of
>>> those myself). Furthermore, all of the OS products released lack  
>>> many of
>>> the properties we are interested in like one way roads, turn and  
>>> other
>>> restrictions, POIs, foot and cycle ways and all the other things  
>>> that
>>> make OSM data such a rich and valuable dataset. So yes, the OS  
>>> data will
>>> clearly not replace any of the "traditional" OSM surveying  
>>> techniques or
>>> be the end of things. But it can be a great basis to build upon.
>>> As a comparison, have a look (assuming you have a timecapsal ;-)) at
>>> what the data of e.g. central London looked like in 2007. It  
>>> already had
>>> surprisingly many roads, but hardly any POIs or other properties  
>>> that we
>>> aim for now. Most of that came later in many iterations of  
>>> improvement.
>>> A single pass of "OSM" surveying is not any better than the OS  
>>> data per
>>> se. Also given that the errors introduced by tracing OS data are  
>>> exactly
>>> the same type of errors introduced by manual "OSM" surveying, i.e.
>>> misspellings in roads, missing roads, outdated roads, ... We need to
>>> have the tools to deal with this kind of maintenance anyway.  It  
>>> is the
>>> iterations that make OSM data what it is, not the "first pass ground
>>> survey".
>>> Creating a blanket base layer from OS data allows us to much better
>>> focus on the aspects that do distinguish us from every other map  
>>> data
>>> provider with having to "waste" as little as possible resources on  
>>> the
>>> "stuff everyone else has" too.
>>> 2) large scale imports and tracing hinders community growth: This
>>> perhaps is the more important of the two arguments, as indeed what
>>> distinguishes us from everyone else is the community and without the
>>> community and its constant iterations  and improvements, OSM data  
>>> will
>>> "bit rot" just as much as all other data. However I don't think  
>>> there is
>>> any clear evidence either way of what non local mapping does to
>>> communities and it remains hotly debated. The negative effects  
>>> claimed
>>> are usually of the form a) The area looks complete, there is nothing
>>> more to do, so why bother. Or, it isn't as much fun to add a POI  
>>> than a
>>> whole new village on a blank canvas. b) I put in all this effort  
>>> into
>>> mapping an area and along comes an import and steam rollers all this
>>> into a mess, I am leaving. c) imports introduce a new class of bugs,
>>> e.g. duplicate nodes or broken connectivity that OSM mappers  
>>> wouldn't so
>>> we don't have the tools to deal with these sort of errors correctly.
>>> b) and c) are specific to imports and thus manual tracing shouldn't
>>> suffer the same issues. a) may be the case, but it is clearly a case
>>> that we need to be able to deal with anyway, as more and more areas
>>> become "complete" by "them selves". And looking at the better mapped
>>> areas, like Germany or some of the UK cities, I don't think there  
>>> is any
>>> evidence that you can't attract new comers into already mapped  
>>> areas. It
>>> is potentially also offset by all those people who simple want to  
>>> use
>>> the data for something like embed a map into their blog or use OSM  
>>> data
>>> on their Garmin, their phone, their game, their ... and will fix  
>>> the odd
>>> bug they discover while doing so, but can't really as it simply  
>>> isn't
>>> complete enough yet.
>>> Other examples of remote mapping have also been fairly successful.  
>>> The
>>> most obvious one was Haiti. It's initial phase was entirely arm  
>>> chair
>>> mapping and had no community at all. Only later followed by on the
>>> ground surveying. Never the less it is generally considered a  
>>> success
>>> and has gained OSM many new mappers.
>>> The other example is mapping during holidays. Lets say I go and  
>>> visit a
>>> mostly unmapped island in Scotland. I'll be able to survey a few  
>>> roads,
>>> add the odd POI make a few mistakes and miss many details. I will  
>>> also
>>> never return to that place again to fix up any bugs I might have
>>> introduced. Should I not have mapped during the holidays as I  
>>> wasn't a
>>> "local mapper" or part of the "local community"? If I do it in a  
>>> foreign
>>> country, I might not even no the local laws.
>>> So again, we as a community as a whole need to be able to deal with
>>> these sorts of issues that also arise from armchair mapping and it  
>>> is a
>>> great test for our ability to create appropriate quality assurance  
>>> tools.
>>> Anyway, far too much rambling from my side already, so I better  
>>> stop now
>>> again. I just felt like countering some of the general negativity
>>> towards armchair mapping and imports.
>>> Kai
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