Soo.... no one commented on what i'd said... Where do those folks get their data... and how is the GPS Drive project mining it?

gpsdrive (at least around version 1.0) was just connecting to various of the web services and downloading chunks of map; The URLs can be constructed if you know where you want to look at.

So... question to Kim and smu... Could this same data be used/mined for the empeg nav project??

It would require a net connection, or knowing where you're going to be, and it'd still be wrong. You're missing what all the people who point at gpsdrive keep missing: it uses raster maps, and the empeg's display isn't suitable for that. Any empeg solution requires vector maps, or serious software to vectorize raster maps... and you won't be running that on the empeg.

Obviously the maps would have to be mined before putting on the empeg... i didn't mean to infer that it would grab the maps on the fly. So does anyone know where those companies get their source data from?

http://mapquest.com/about/partners.adp is probably about complete for MapQuest at least, and from it you can gather they start with USGS and Census data for the U.S., and who they use for their other data.

This would imply MapsOnUs uses *only* the Census and USGS data thus far, probably because it's free, potentially through a partner to get enhancements since the base data gets out of date and of course has errors.

Those folks get their data from NavTech. Almost *all* the commercial mapping routing software in the US uses NavTech data. If you scoop the data from those sites that would be illegal. I sent one of the NavTech reps in smu's direction months ago. In terms of cost, if the project split the licensing fees with a few other groups doing the same thing, then certainly it would be very affordable.

Calvin

My contact at NavTech tells me that the TIGER data is notoriously inaccurate. That is why they have an army of drivers that drive the roads and streets of the entire country verifying the accuracy of the data. They go in teams of two, with a driver and a mapper. They ensure that one way streets are real, that changes in the road system is reflected. The updated data is proprietary. In addition, they use satellite maps and other data to make sure everything is right. Because of this army of people, the NavTech data is the most accurate but also the most costly as you can imagine. They cover north america from canada all the way down to latin america and western europe.

Calvin

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My contact at NavTech tells me that the TIGER data is notoriously inaccurate.

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It's quite obvious if you spend any time at all browsing the Census Tiger mapping site for any area you might be familiar with. And ignoring the question of the data being out of date, some USGS maps weren't accurate when they were current, either. A highway ramp near me is missing, probably photorevised away by the looks of it, despite having existed continuously since about 1952.

NavTech isn't perfect, either, but they certainly are (demonstrably) better than raw Tiger.

They ensure that one way streets are real, that changes in the road system is reflected.

Well, they must have a base camp at the Big Dig then...the road layout seems to change daily.

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Well, they must have a base camp at the Big Dig then...the road layout seems to change daily.

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One week I was in Boston for a conference. I showed up at South Station, went out and got a cab. When I came back the next week, the area where the cab stand was the week before was gone. There was a big hole there

Oh man.. the big dig... Forget having GPS if you live in that area... it'd be worthless. I've visted there 3 times in the past year and it's completely different every time. The streets there are mangled as it is...

Maybe we can convince NavTech to let empeg owners 'volunteer' their GPS tracking info that could be used to validate their maps automatically. Users could even use the empeg to 'annotate' the map...

If still looking for the right person:
I live about 100km away from Schwabach

Have you seen this site on the GDF specification yet?

http://www.ertico.com/links/gdf/gdf.htm