OpenStreetMap
When I look at our map here in Germany, I see at lot of astonishing spots where a lot of detail is available. On the other hand, there are still many white spots.
So I tried to estimate how many contributing members our project needs in Germany to get a good 100% coverage in the foreseeable future.
Germany has a size of 357021 km^2 and about 82 million inhabitants (from baby to old people).
Now let's assume that somebody can map 20 km^2 i.e. an area of 4 by 5 km without dedicating all his spare time and the rest of his life to mapping. ;-) It may be less in big cities and more in rural areas with only small villages, so I think this evens out. (4 by 5 km sounds reasonable to me. I'm involved in a larger area, more like 8 by 10 km, but didn't and don't have to do everything there myself, luckily.)
This means we need about 18000 people mapping for OSM in Germany or 0,02% of the total population.
The OSM statistics for today say there are currently 28613 users in total.
I don't know, doesn't sound like too many people are needed, but can we reach enough who are both motivated to take the work of mapping AND can handle the technology, i.e. using some GPS capturing device, uploading to the PC, using the editors?
What do you think?
Discussion
Comment from NicRoets on 22 March 2008 at 16:49
Last time I checked roughly 1 out of 100,000 British are active mappers and 1 out of a million South Africans are mappers. This is not nearly the 1:5000 ratio you want, but these maps are already quite useful.
Instead of targeting km^2, we should target km of roads. And then we should weigh it according to the amount of traffic those roads carry, it which case we are already halfway there !
Comment from HaraldK on 24 March 2008 at 15:43
Due to the horrible easter weather, I had time to learn about the data available (and partly provided on unclear but restrictive terms) by the Landesvermessungsamt Nordrhein-Westfalen (http://www.gis3.nrw.de/DienstelisteInternet/). Browsing through this data shows that this is real great data. It has every detail you ever want. While I really like the OSM initiative and find it quite entertaining to go mapping by bike, I must say that it is really sad, that this great set of data acquired and prepared by spending a lot of tax money is not really publicly available.-(
Comment from amai on 25 March 2008 at 18:38
Well, from my view on the database in Germany I conclude that the bigger cities have a "good" coverage, but the rural areas are mostly complete white spots featuring only a few major roads, if at all.
So by simply doubling the number of contributors it wouldn't double the content probably...