[OSM-talk] [OSM-dev] FW: OSM stats quote for a paper

[Mike Collinson]

At 02:51 PM 21/09/2007, Frederik Ramm wrote:
>Hi,
>
>> Hi Andy, I am writing a short paper and citing OSM as an exemplar  
>> of new,
>> creative mapping practice. I'd like to quote a statistic to show  
>> the level
>> of effort people are ging to OSM. Is it possible to (easily) calculate
>> length in kilometres of roads mapped in the last six months say?
>
>His request is difficult to answer because what does "mapped"  
>actually mean? Plus, with all the TIGER and AND imports, any world- 
>wide figure would be heavily distorted (or you would have to filter  
>those).
>
>I have a planet.osm UK+Ireland excerpt from 07 March and the same  
>area for 05 September, then counted the length of roads. Here's the  
>result (looks broken in mail but easy to create a CSV from it if you  
>want to open it in OpenOffice etc - all figures in metres):
>
>"highway class","March '07","Sep '07","difference"
>"unclassified        ",12145635,26974997,14829362
>"primary             ",13307013,23149042,9842029
>"trunk               ",8942197,18199030,9256833
>"residential         ",8141093,17858331,9717238
>"secondary           ",6638616,15045177,8406561
>"motorway            ",7102946,7496052,393106
>"tertiary            ",726593,6399821,5673228
>"footway             ",2844692,6060560,3215868
>"cycleway            ",573560,2183086,1609526
>"bridleway           ",860739,1728260,867521
>"service             ",624702,1726657,1101955
>"motorway_link       ",537020,845698,308678
>"track               ",177062,696127,519065
>"minor               ",695783,687587,-8196
>"trunk_link          ",217150,523527,306377
>"fixme               ",0,201922,201922
>"byway               ",102622,178680,76058
>"unsurfaced          ",229358,161657,-67701
>"primary_link        ",87764,119645,31881
>"pedestrian          ",26538,109205,82667
>"footpath            ",53340,32123,-21217
>"total",64034423,130377184,66342761
>
>So if that data is to be believed, around 66 thousand kilometres of  
>roads have been added in the UK and Ireland during the last 6 months.  
>(Reality check, anyone - is that figure probable?)
>
>That could come close to what he wants. But note:
>
>* A lot of work goes into doing amenities, coastlines, railroads,  
>forests, and waterways - not covered by this figure.
>* Stuff that gets deleted reduces my figure (but the work has been  
>done so the figure is too low).
>* Dual carriageways are counted double.
>* I have omitted lots of strange highway "types"
>* everything might be wrong for some reason or other ;-)

 From what I understand of marketing, when in doubt, always pick the largest number. I'd say the estimate above is a pretty damn good one from that perspective.  I'd suggest the worldwide figure should indeed include currently included TIGER and AND data. If it appears on an OSM map, it is "mapped"!

Mike
Stockholm