[Talk-GB] [OSM-talk] London party maps

[Dave]

On 1/25/07, Robert (Jamie) Munro <rjmunro at arjam.net> wrote:
>
> Dave wrote:
> > Presegmenting on the applet can actually do more harm than good, given
> > the large numbers of roads that get marked but aren't there, the roads
> > that are one way but you don't know which way the segments go, having to
> > pick out segments that form a way and were defined in opposite
> > directions etc.
>
> I think it's worth trying with and without presegmenting, and seeing
> which works best. Certainly in the suburbs, it's much easier, and I have
> presegmented loads of where I used to live, some of which was aided by
> memories of the area, but lots wasn't. A quick drive with liveGPS
> enabled JOSM would finish that area in no time - you could even run a
> Travelling Salesman algorithm on the segments to decide which route to
> drive (anyone fancy adding that to JOSM?)


If you're using JOSM and GPS tracks then this is true.

The problem is I can pretty much ignore the output from my GPS, it's
probably wrong in the level of detail that's going to be important in these
areas. Here's an example of what someone has done from GPS in the area
across the road from where we're gonna meet:
http://www.openstreetmap.org/index.html?lat=51.513512344322265&lon=-0.10699346778691769&zoom=17
hit edit and see if you can figure out what's going on.
Now imagine how you would have presegmented it.
At this point my GPS will be going wild and I woudn't have a clue what point
was relating to which presegment, especially if I've missed a road or two
(or added one) which means I can't even count along.
It's much easier here to just dump the GPS in a nearby bin and start
scribbling on a aerial photo printout :-). Once you're doing that,
presegmenting anything is a complete waste of time really -- you didn't gain
anything.

My main problem with presegmenting is that I can't do it. I know I can't
tell the difference between a shadow and a road half the time. :-)

(I'm also missing the car!)
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