3 ms·

I spend a decent amount of time exploring strange parts of the world, and in my experience with several different phones in several different countries is that

I spend a decent amount of time exploring strange parts of the world, and in my experience with several different phones in several different countries is that GPS (assuming your phone is charged and you're not in a cave/underground) is always good enough to get you out of wherever you are. To give some examples, in the past twelve months or so I've navigated by GPS (using Google Maps to visualize my position) in mountains in Iran, semi-rural Ukraine, forests in France, middle-of-nowhere Canada, and forests in America. In case you think that my GPS worked just because I had good devices, I've used everything from a nice iPhone 6+ to a decent Galaxy S5 to a crappy Huawei P8 Lite which I bought for $65 used. I'm not sure how you can quantify GPS as "80% accurate". Does that mean 20% of the time it puts you in the next state over? Or that it's 200 meters off? I can't think of a reason why your GPS position would be wrong... it's not as if physics just breaks down in the Rockies. In order to get such tremendously poor results, I have a feeling that you did something like turning off GPS (which forces your phone to rely on cell tower triangulation) or using GPS where it doesn't work (like in a cave.) If the actual, raw values from your GPS were wrong I would be extremely surprised.

maxerickson 10y ago
The accuracy statement is about the maps. Google Maps can be pretty spartan in wild parts of the US.
codingdave 10y ago
The 80% accurate statement is about the maps themselves. Google maps will show a road that just doesn't exist. Or you will be driving down on a road that isn't on the map. Or the map will show the road going through, even though you are at its end, looking at a cliff. It will show intersections that do not exist. In some cases, I can tell they used old data. I know one road in particular that did exist 30 years ago, but the forest service deliberately closed off when a rock quarry closed, and it has been re-forested. It still shows on the maps. Another that shows on the maps was planned to be built by the BLM, but never was... yet the map shows it. So I'm not sure exactly what data set they built their maps from, but clearly it did come from data, not actual exploration... because the dirt roads in the American west are just not accurate.
- ghaff 10y ago
  In general, the information on maps about dirt roads in the US West can be hard to rely on. Some of the information, as you say, is just out of date. But it's also the case that dirt roads range from well-maintained and graded to you'd better have a jeep and know how to drive it--and the distinction isn't always obvious on a map (digital or otherwise). Road conditions also vary based on season, weather, and how recently there's been maintenance work done. Someone stated in an earlier discussion that part of the issue is that a lot of this dirt road data is from US Census TIGER data, which was never intended for automotive navigation. [1] [1] https://news.ycombinator.com/item?id=11657931 https://news.ycombinator.com/item?id=11657931

maxerickson 10y ago

The accuracy statement is about the maps. Google Maps can be pretty spartan in wild parts of the US.

codingdave 10y ago

The 80% accurate statement is about the maps themselves. Google maps will show a road that just doesn't exist. Or you will be driving down on a road that isn't on the map. Or the map will show the road going through, even though you are at its end, looking at a cliff. It will show intersections that do not exist. In some cases, I can tell they used old data. I know one road in particular that did exist 30 years ago, but the forest service deliberately closed off when a rock quarry closed, and it has been re-forested. It still shows on the maps. Another that shows on the maps was planned to be built by the BLM, but never was... yet the map shows it. So I'm not sure exactly what data set they built their maps from, but clearly it did come from data, not actual exploration... because the dirt roads in the American west are just not accurate.

ghaff 10y ago
In general, the information on maps about dirt roads in the US West can be hard to rely on. Some of the information, as you say, is just out of date. But it's also the case that dirt roads range from well-maintained and graded to you'd better have a jeep and know how to drive it--and the distinction isn't always obvious on a map (digital or otherwise). Road conditions also vary based on season, weather, and how recently there's been maintenance work done. Someone stated in an earlier discussion that part of the issue is that a lot of this dirt road data is from US Census TIGER data, which was never intended for automotive navigation. [1] [1] https://news.ycombinator.com/item?id=11657931 https://news.ycombinator.com/item?id=11657931