tomtom on the Neo1973

Ian Stirling openmoko at
Mon Apr 2 21:07:26 CEST 2007

Jonathon Suggs wrote:
> Andrew Turner wrote:
>> Caching googlemaps tiles, and not through their client, is a violation
>> of their Terms of Service.  Same for all the other providers. 
> <snip>
> Here's an interesting question.  What if you constantly logged your 
> position (while driving).  Then when you got back home, you could upload 
> all of your data back to your desktop.  Would it be legal to have a 
> script analyze that data, and make "suggestions" from public sources (ie 
> google maps, mapquest, etc) as to what roads you traveled.  Once you 
> verified that information it could automatically upload back into 
> OpenStreetMaps (OSM)?  Basically just reducing some of the time/effort 
> required to upload information into OSM.

Not really, no.
Street names are in some cases faked, to catch this very thing.

At the moment, the upload process for OSM works like either:
Upload your GPX file to the server.

This then appears as a background trace in most map editors - lots of 
little dots .
This is of use, for those that then go and put in the ways (highway, 
waterway, cycleway, outline of a wood), if they have local knowledge of 
the road in question. (they are commonly the same person).

In the image shown, the GPS traces are shown as little white dots - the 
road to the right is one journey. The other roads each have several 
journeys, which help define the accurate course of the road.
For a simple long-distance road - say the vertical one on the 
right-hand-side, it may have several tags, for example

As it's a trunk road, the A92, and each way is one way only - you can't 
do a u-turn as there is a central reservation.

And yes, this means that for a good quality map, someone has to decide 
where on the GPS trace the road goes, using local knowledge. If the GPS 
trace is simply a road, a cross-country run, or a train, and where 
Bruntun Place turns into Bruntun Street, by looking at signs and either 
remembering, or photographing them and then consulting the photos which 
are automatically glued to the map by timestamp.

Even 'dumb' users, for example, ones that are not going to be willing to 
enter streetnames, but might be persuaded to push 'car' on the 
screensaver when they are in their car, are of use.

You can extrapolate some probable data out of multiple tracks, 
especially accurate road position, number of lanes, junctions (where 
people often stop).
Doing so out of one track is comparatively really hard.

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