[Openstreetmap] RoadMap map generator / editor

[Simon Hewison]

Tom Carden wrote:
> So the ideas I'm after are thoughts people have on merging an existing 
> road with a GPS track.  Or in OSM's case, an existing road with hundreds 
> of GPS tracks of that road.  When do we stop refining the shape?  How do 
> we take noise into account?  How much priority do we give to the most 
> recent data?  ( e.g. if a new roundabout/intersection is added, and we 
> have 100 GPS tracks which say there isn't one, but 1 GPS track for today 
> which says there is - can that be automatically merged?)

Good example here. At
Lat:51.6992479965827 Lon:-0.2262137092125

(A1(M) south, near Potters Bar), there's a parallel road that is within 
a typical GPS error of the main road. It follows the motorway for a long 
way.

How would the road merging code know that the track was taken while 
driving south along the A1(M) and not the parallel Swanland Road? The 
only way I can think is that it would have to take context into account 
(the only sane way to get onto the A1(M) southbound is via a slip road, 
and Swanland Road starts where there is no specific interchange with the 
A1(M))

You certainly wouldn't want the code to swing Swanland Road towards the 
A1(M), or vice-versa.

-- 
Simon Hewison