Hacker News Reader

Comment by bsder | Hacker News Reader

> I don't get how Google even thinks this is a road, or what data it is using to discover it. Its nowhere on any map that I know of!

I suspect that someone holding an Android phone simply drives the path.

If you're Google, which will you trust more:

1) A bunch of sources of varying correctness which may/may not have been tampered with.

2) Actual GPS coordinates from your OS saying "Hey, somebody drove here."

View on HN

I don't think gmaps actually does that. We have a 20 meter stretch of road near our house that connects two other roads. Google, for at least the last five years, has refused to believe that this road can be traveled, having everyone take a detour. Hundreds of cars are taking this non-existing road every day, but Google still hasn't taken the hint. (Probably preventing quite a bit of through-traffic in our neighborhood, so we're actually rather happy about this. :-))

20 Meters is quite short, so assuming a certain speed, there might only be a few GPS probes for each pass, that might also look as if they were outliers.

But how does that explain everybody getting from a to b without taking the two minute detour?

While I work at a company that, among other things, builds a navigation system (with a twist of doing load balancing on streets; called NUNAV Navigation), I'm not really an expert in this topic. From working with GIS and GPS quite a bit, I know though, that a lot of things, while they are working very well, are not as exact as they look (e.g. bad GPS signal, especially when driving with low speed, map matching, etc.)

Maybe someone else can comment in more detail.

I don't know if Google Maps pays much attention to Android users frequenting a particular path. Where I live you need to take a particular route else you end up at closed gates. Despite hundreds of people using this route every day for years Google will still try to take you via a different route that takes you to a closed gate. Other mapping software gets it right but we have to provide specific route instructions in case anyone uses Google and ends up at a dead end. I have noticed this all over actually, with Google trying to take short cuts that don't work vs following well-established routes.

I thought that too, but the irrigation district locked a gate when they finished up in October and yet it is still popping up. So if they are using phone traversals then its all foot traffic and that is more terrifying than it being detected via satellite images!

Reply on news.ycombinator.com