Google Navigation route question

Discussion in 'Android Apps & Games' started by AppointedSole, Sep 24, 2010.

  1. AppointedSole

    AppointedSole Member
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    Jun 12, 2010
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    I made the switch to Google Navigation after using Sprint's Navigation application for a few years on my previous BlackBerry and love it! It's my primary GPS application.

    So, here's my query... While I was tinkering with it today, I noticed the option to choose an alternate route.

    We are going to be driving to LA a little later this evening and the default route Google Navigation chose was longer in both time and distance compared to one of the alternate routes (total of three routes).

    The default route gave said it is 332 miles and 6hr/9min. When I pulled up alternate routes, the second option was 325 miles and 5hr/49min. The third route was over 7 hours long.

    Do you guys know what methodology Google Navigation uses to pick the default route? Why the longer route?

    Thanks everyone!! :)
     

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  2. kencrudup

    kencrudup Well-Known Member
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    Nov 11, 2009
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    It adjusts based on what it knows of the route's traffic history for the times you'd be expecting to travel. Although it might be longer right now, by the time you'd've gotten there it might be faster overall.
     
  3. KingFatty

    KingFatty Well-Known Member
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    It also may take into consideration the type of roads (preferring highly-traveled highways) and the simplicity of the path (fewer turns/easier to navigate highways).
     
  4. sharkerbaby

    sharkerbaby Well-Known Member
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    Google Navigation route selection has confounded me from the beginning. I live in the far north burbs of Chicago and travel daily to a north burb an approximately 45 minute drive. It refuses to select the tollway route 9 out of 10 times. I do not have the avoid tollway or the avoid highway options selected so that's not the problem.

    I have made this drive for over 15 years and usually travel during non peak times so I know the routes well and the effects of traffic but use the navigator to identify unusual traffic incidents. Even when I "force" it to route via the tollway by getting on the tollway and forcing a reroute calculation, it tries to get me off as soon as possible giving me a sometimes very convoluted route to get to my destination. I can say from careful observation that quickest route does not seem to be heavily weighed in it's route selection and I don't believe shortest route is its preferred choice either. I just can't figure it out.
     
  5. UncleMike

    UncleMike Well-Known Member
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    I don't know how Google chooses a route, but if you calculate the route on their web site, your can click the "report a problem" link. There may be a bug in their routing algorithm, or an error in their map database that's causing the problem. I've had a lot of success using this link to get road names and turn restrictions corrected. If you point out the problem to them they should investigate and get back to you. Any time I've pointed out an error (as opposed providing information where it was previously missing), they have always gotten back to me with a "you were right!" message, followed (a couple of months later) with a link to the former problem after the correction has been made.
     
  6. sharkerbaby

    sharkerbaby Well-Known Member
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    hmmm, never thought of checking the route selection via their website. I'll try it and see what happens. thanks for the suggestion.
     
  7. UncleMike

    UncleMike Well-Known Member
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    I would expect it to be the same, but it gives you an easy mechanism for reporting problems.
     
  8. Roze

    Roze Hiding behind a mystery
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    I was wondering if there's an option in Google Nav that picks the fastest time? I've only used the Nav on one route and it always picked the shortest route. Though the shortest route (in roads) take 30 minutes while the fastest route (highway) is a couple of KM longer but takes 20 minuntes.

    I actually tried to force it to take the fastest route and it made me lost the first time :( It kept on telling me to go back to the original route that's the shortest distance and kept on re-calculating for the shortest distance (it seems) until I pass that point.

    My brother's Tomtom has his set up to 'fastest route' I've had both run at the same time when driving to compare if they pick the same routes. Anyways, can't seem to find that option on the Navigation.

    Thanks
    -Roze-
     
  9. jev

    jev Well-Known Member
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    You can choose to avoid main roads or avoid tolls or have it calculate a couple of alternative routes from the menu but that's it. There are no options to choose between "fasted", "optimal" or "shortest route". Those choices just aren't implemented.

    Comparing to other navigation systems will show a lot more differences than you may have thought. Google navigation is just a very basic router, nothing fancy.
     
  10. Roze

    Roze Hiding behind a mystery
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    Oh how can I do that? So there are various alternate routes to the same designation that I can choose from or do I have to input them?
     
  11. Szadzik

    Szadzik Well-Known Member
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    Open Navigation>Settings>Avoid main roads and avoid tolls is right there.
     
  12. Roze

    Roze Hiding behind a mystery
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    OK, would 'avoid main road' = highway? :)
     
  13. jev

    jev Well-Known Member
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    I guess so. Just give it a shot - it won't cost you anything ;).
     
  14. A.Nonymous

    A.Nonymous Well-Known Member
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    I've found Google Nav's route finding to be kind of questionable myself. It seems to me that it finds routes like a rookie route finder. For example, I had it find a route from my home to my office. It found a simple route that sticks to the main roads. I know a better route that sticks to some residential streets and is faster. So I started driving my route. Google Nav consistently re-routed me on the fly, but kept re-routing me back to it's initial route. This would've added another 10 mins to my time easily, but it kept routing me back to the original route. It was like it thought it was lost and wanted to backtrack to where it started from.
     
  15. Kalnel

    Kalnel Member
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    Oct 5, 2010
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    I have had the same problem as A. Nonymous. I've had it recommend doing a a u-turn by exiting and re-entering a highway, rather than offering me a new route.
     
  16. A.Nonymous

    A.Nonymous Well-Known Member
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    I had it do something dumber than that the other day. I was driving through an unfamiliar area. It told me to get off the highway at a particular exit so I did. The next direction it gave me was to get back on the highway. I was like WTF?
     
  17. UncleMike

    UncleMike Well-Known Member
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    I've had similar experiences with my TomTom too - usually due to traffic on the highway.

    I've also had Google Maps Navigation tell me to take a ramp onto a side road, only to turn on the side road and then turn back onto the road that I just left.

    Any navigation app will have bugs in the routing algorithm, but I think most of the strange routing we see as users comes from error in the mapping data rather than the routing calculations.
     
  18. pavirotten

    pavirotten Well-Known Member
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    Nov 28, 2009
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    I have made a drive from Ohio to North Carolina twice since September and will do again at the end of this week. Each time I start out, either on the way there or on the way back, Google has given me a different route EVERY TIME when in NC. Once it took me down these two lane roads with absolutely no signs, but no traffic as well, once I within an hour of my destination. Another time, it took me down major highways the whole way.

    As far as it figuring out the fastest route based on traffic patterns and time of day, I find that extremely hard to believe. Google Nav took me right past Fort Bragg at 5:00PM on a Friday. It took me 30 minutes to go five miles when there were faster ways to get to my destination.
     

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