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XMNavTraffic & Route Guidance

Discussion in 'Gen 3 Prius Audio and Electronics' started by Tideland Prius, Aug 4, 2011.

  1. Tideland Prius

    Tideland Prius Moderator of the North
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    XM recently decided to update its system (and I guess some or most of you had changes in your area too) and for us in western Canada, it means additional traffic flow information or even traffic flow & incident information for the first time.

    While it's a nice feature, I wonder if it affects the navigation system's iQ routing algorithm. Now I'm not saying if there's traffic, it'll re-route me. I'm saying that there's light traffic (green all the way to my destination) but if the navigation had to choose between a faster route (on paper) with no traffic information and a longer route with traffic information (all green), it would route you through the longer route. Has anyone noticed that?


    I live between two main streets, one with and one without traffic information. I needed to get to a place just east of downtown. The quickest route would be taking the road without traffic information and ride the perimeter, staying out of downtown to my destination. The navigation system wanted to take me on the road with traffic information, route me through downtown (nearly all the way to the other side) and then back out of downtown to my destination. Seems like a ridiculous route (Esp. given it was close to 4pm that day and there's no way I'm going downtown at 4pm on a weekday) and would've taken much longer.

    Does anyone know if there's an algorithm built in such that it would rather take the longer route knowing traffic is light than to take you on a road with "unknown" traffic density.
     
    #1 Tideland Prius, Aug 4, 2011
  2. darogers

    darogers Junior Member

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    In general I've had little luck with the navigation system accounting for traffic. I've tried to reroute several times due to traffic but 90% of the time it upts me back on the same route.
     
    #2 darogers, Aug 28, 2011
  3. Tideland Prius

    Tideland Prius Moderator of the North
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    Can't say I have either (But then again, traffic is limited in Canada so if it does want to re-route, I'm not sure if it knows how because there's no traffic information outside of the main highways so it won't know what to do). This is why I'm asking the question above and whether it ignores roads without traffic information.
     
    #3 Tideland Prius, Aug 29, 2011
  4. Roland1555

    Roland1555 Senior Member

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    From my experience, and like you, here in Vancouver there have been upgrades to indicate traffic flow, the system will still ick routes based upon presets only.

    that is, if you pick shortest, it will still do that, but, if you also have enabled reroute for traffic, then a pop up will allow you to take the advise and ossible new route. It tells you that it has downloaded new traffic info, if you agree to let it route around an incident, then it restarts and says that the guidance will start now etc,and you go off following a modified track to your destination.

    This worked great around LA for me and kept me for the most part from never sitting in a clogged freeway jam.

    South of Vancouver along parts of highway 1 though, I ignore it sometimes as I find it like to reroute you into short collector lanes then drop you back into the main slowdown. As I look at people who do that as cheaters, I don't do that myself... but fell victim to it thinking it was going to take me right off the highway before I learned otherwise.

    Roland.
     
    #4 Roland1555, Sep 5, 2011
  5. Tideland Prius

    Tideland Prius Moderator of the North
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    So if you leave it on the default (so Quickest rather than Shortest), would it intentionally route you through a road with traffic information even though there's another route that's faster but because there's no traffic data on that road, the nav doesn't know and assumes worst-case scenario?
     
    #5 Tideland Prius, Sep 6, 2011
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