Reply to post: Re: OpenStreetMap

Google can't innovate anymore, exiting programmer laments

handleoclast

Re: OpenStreetMap

@AC

This is a huge issue to me as I have no way to determine where their mapping is fantastic and where (like local to me) it is badly wrong, so I can't trust any of it.

This can have numerous causes. The offset you mention could be due to your own GPS (cheap units can take a minute or two of being stationary to settle) or the mapper's GPS or the parallax of the aerial imagery used, or the supplier of aerial imagery got the offset wrong (mappers can compensate for offset errors in aerial imagery if it's obvious). The essential topology ought to be reasonably good even where the absolute co-ordinates are offset.

Where OSM can beat Google (if a mapper puts in the effort) is greater detail. In my area there are streets where one side has numbered houses and the other side has named houses (no number ever assigned). One street has this arrangement except when it turns a corner the sides swap between names and numbers. Google is no help if you're given the name of a house that's on a long street, and often the house numbers are wrong (sometimes wildly wrong). Google occasionally gets the extent of streets wrong when two individually-named streets join to form one longer street. Google even gets street names completely wrong, occasionally.

If your local area is wrong, there's something you could do to fix it. That may not benefit you much, but it may benefit others and they, in their turn, may improve the mapping in an area you want to explore one day. That's one of the fundamental properties of Open Source: you can contribute and you gain from the contributions of others.

BTW, Ordnance Survey occasionally gets it wrong, too. They're smart enough to claim their errors are actually protection of copyright, so if they see those errors on somebody else's mapping they can assert copyright violation. A very smart way of covering up your errors. :)

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