[OSM-talk] Mapping 'risky areas'

Mike N niceman at att.net
Mon Feb 21 16:10:39 GMT 2011

On 2/20/2011 8:48 PM, Hillsman, Edward wrote:
> My impression is that in most US cities, the places where a lot of POIs have been mapped from field work are in the older, gridded, more pedestrian-friendly parts of the area. This could be because there are more interesting things there, or that people who live there tend to be more likely to have personalities that lead them to get involved in OSM, but it also could be that it is just easier and safer to map there. I recall seeing a piece of research noting that areas with high crime rates tend not to get mapped in OSM, so these would be exceptions to the older-area trend, but support for the hypothesis that walkability matters a lot (high crime means not safe means no mapping on foot).

I have seen this effect also - there are nearby areas that I will never 
survey because they are too risky.   Even in a vehicle, I would not want 
to risk a breakdown.

   For the areas that are unfriendly to pedestrian and bicycle, I have 
used video from a vehicle.  The results are minimally helpful because of 
the time it takes to locate features on the aerial map.   I have just 
gotten a Contour Vidcam with a GPS - you can export the GPX trace with 
embedded video frame information.  The track loads in JOSM, and I would 
like to write a plugin to allow selection of frames from the track, as 
well as highlight the track location based on the video location.  I was 
going to take the simplest route however - the result might work only in 
Windows; I'm not sure there is a Java cross-platform media 
interface/control library.

   From a bit of experimentation, 2 of these vidcams would capture 
street signs on both sides of the street in a standard residential 
housing area in a single pass, or one vidcam mounted at an angle would 
require 2 passes.  Urban canyons would still have too many GPS echoes, 
and would not be quite as useful.

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