I downloaded your 24k topo for Garmin prior to purchasing the Garmin 24k. They both share a common deficiency because I suspect you use the same government data source: Compared to the last version of Garmin 100k, nearly 80% of the backcountry roads are gone in the 24k.
Some believe this is by design, on the part of our government.
Jerry Steele
NOT SO.
The printed USGS 24k maps show these roads; however they are not all available in ditital form and you may have noticed that few roads/streets on the printed maps have names. Most GPS users are wanting names and addresses for the roads/streets in their GPSrs.
USGS 100k maps were panelled from the 24ks. Thus the road/street network is as complete as what was shown on the 24ks for the same area. I made an overlay/transparent mapset from the 100k transportation files and it is available on this site. This data is decades old, as are most of the 24k maps.
The free data we have available for roads/streets usually comes from the Census. They created it and use it to locate where people live for their census counts. If there are no residents along a backcountry road, it would be unlikely funding would be available for the road to get into their database. Some States have road/street data available on their GIS websites; however, the currentness, completness and attributes are quite variable.
Garmin's road/street data is licensed from NAVTEC. The money is where people live, where the businesses are, etc.
To add to what maps4gps said, making routable maps, of the sort you buy from Garmin is really hard work to do as DIY mapping.
Also, regarding backcountry roads. There are a lot of roads shown on maps, digital maps that aren't reliable for travel. My first version of CN had the road to Toroweap Overlook, North Rim, Grand Canyon running over a 4WD track west of Vulcan's Throne, instead of the slightly better 2WD road that lead to the campground. Aparently, they had just incorporated some bad Census data, because they certainly didn't drive it with instrumentation.
I still think it's a government conspiracy! ;D
Nope.
Its them dang commies.
Sorry, but you're both incorrect.
It's those mischievous gremlins!
Quote from: maps4gps on June 16, 2010, 08:09:02 AM
NOT SO.
The printed USGS 24k maps show these roads; however they are not all available in ditital form and you may have noticed that few roads/streets on the printed maps have names. Most GPS users are wanting names and addresses for the roads/streets in their GPSrs.
USGS 100k maps were panelled from the 24ks. Thus the road/street network is as complete as what was shown on the 24ks for the same area. I made an overlay/transparent mapset from the 100k transportation files and it is available on this site. This data is decades old, as are most of the 24k maps.
The free data we have available for roads/streets usually comes from the Census. They created it and use it to locate where people live for their census counts. If there are no residents along a backcountry road, it would be unlikely funding would be available for the road to get into their database. Some States have road/street data available on their GIS websites; however, the currentness, completness and attributes are quite variable.
Garmin's road/street data is licensed from NAVTEC. The money is where people live, where the businesses are, etc.
Thanks you for the post.
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