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Routing errors in a 920

 
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      09-26-2009, 04:56 AM
I experienced a couple routing errors on my last trip using my 920. Below is what I sent TomTom as a question from my TT account. Has anyone else experienced these kinds of errors (it's the first time I've seen either of them)? And is there a fix for the errors?

--------------------------------------------------------------------------------------------------

App. 8.351, Map North America 835.2419

There appear to be two routing errors:

1) A route from Cascade Locks, OR, to The Dalles, OR, is routed correctly. If I do "travel via" Hood River, OR, the route remains unchanged (does NOT pass through Hood River), even though the map shows there is the little yellow flag in the center of Hood River.

2) If I use the Cascade Locks, OR, to The Dalles, OR, route, then do a "find along route" for Wal-mart, the Wal-mart in Hood River is not found. The Wal-mart is right next to the route (less than 100 feet off the Interstate 84), and should be found.

Is this problem with my 920? Or is there a map error or routing algorithm error that TomTom must correct? If it is the later, when can I expect these routing defects to be fixed?
 
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dhn dhn is offline
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      09-26-2009, 12:13 PM
What restrictions, if any, do you have under planning preferences? That may be impacting the routing. Do you have IQ routing active?

No poi set is totally complete. Thus, the missing Wal Mart may not be included at all.
 
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      09-26-2009, 02:59 PM
There think there might be some routing algorithm errors in the map/GPS. When I use my 920 to gride me to a place, I can always find another route(by myself, not with the GPS) that is ~5 minutes(its only like 30 to 40 minutes driving so 5 minutes is a big different) faster than the route that tomtom takes me(with the fastest route option and IQ route enabled) From what I see, tomtom likes to stay on the same road and make fewer turn which they think is faster.(my opinion)

Last edited by zengshengliu; 09-26-2009 at 03:02 PM..
 
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      09-26-2009, 06:29 PM
Quote:
Originally Posted by dhn View Post
What restrictions, if any, do you have under planning preferences? That may be impacting the routing. Do you have IQ routing active?

No poi set is totally complete. Thus, the missing Wal Mart may not be included at all.
Planning preferences:
- always plan for limited speed (60 mph)
- ask me if I want to switch to faster route (I don't have live traffic, anyway)
- ask me when there are ferries on my route
- when there are HOV lanes on my route
- ask me when there are unpaved roads on my route

None of those are activated with a route that goes through Hood River, OR. I can route directly to Hood River without a problem.

I am using IQ routing, which has been a big improvement, generally.

The Hood River Wal-mart is in the TT POI set in my 920, and I can route to it directly without problem.
 
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      09-26-2009, 06:52 PM
Quote:
Originally Posted by zengshengliu View Post
There think there might be some routing algorithm errors in the map/GPS. When I use my 920 to gride me to a place, I can always find another route(by myself, not with the GPS) that is ~5 minutes(its only like 30 to 40 minutes driving so 5 minutes is a big different) faster than the route that tomtom takes me(with the fastest route option and IQ route enabled) From what I see, tomtom likes to stay on the same road and make fewer turn which they think is faster.(my opinion)
"Stay on the same road" might be the key. Sometimes I can find a quicker route manually, but it's almost always only a minute or two at most. The key factor seems to be the direction I'm heading (or the direction I WAS heading if I'm stopped) when I have my 920 do a "navigate to". Rather than insist I do an immediate U-turn, the 920 starts the routing in the direction I seem to be going. If it can get me turned around in a block or two, it does that; otherwise, it will start with the "turn around as soon as possible" litany.

The "problem" is most often encountered coming out of a parking lot. For example, because I was moving north in the parking lot before I got to the exit from the lot, the 920 chooses that direction to begin the routing. If I know I have to go south, I'll turn south as I exit and the 920 will reroute, finding the shorter route.

What is fascinating is to have it choose different routes for the same start/finish, depending on the time of day! I see that mostly in big cities, where traffic density varies considerably with time, and rarely in my smaller hometown. Even here, the route can be quite different at 5 pm compared to 10 pm, and I've been impressed with how it can do a better job than I can.
 
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      09-29-2009, 04:14 AM
I've never seen Tomtom ignore a waypoint like that before. It appears that the waypoint is ignored if you put in the Hood River town, and the waypoint is honored if you put an address within the town. If you use a specific address, it doesn't seem to have any problems.

As far as missing the walmart on the side of the road, the "along route" preference is detour-time based, not distance-from-road based. So if the Walmart is more than 10 minutes out of the way (even if next to the highway), the "find along route" won't find it.

Regarding uturns, it is a known issue. See here.

 
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      09-29-2009, 03:55 PM
I haven't seen this routing problem before, either, but it is not just Hood River: Route from Richland, WA, to Spokane, WA, via Sprague, WA, and it does the same thing. The waypoint in Sprague is not used.

--"As far as missing the Wal-mart on the side of the road, the "along route" preference is detour-time based, not distance-from-road based. So if the Wal-mart is more than 10 minutes out of the way (even if next to the highway), the "find along route" won't find it."--

The difference in time from Cascade Locks, OR, to passing Wal-mart driving on the I-84 interstate versus Cascade Locks, OR to the Wal-mart in Hood river is 1 minute by TT's calculation. The route leaves I-84 about the interchange about 0.8 miles before the Wal-mart.

I was trying to find Wal-mart "along the route" using the "search POI" function. If I try to find "along the route" using the "Retail store" category, it DOES find the Wal-mart! So, it appears there is a problem in the "Search POI" function.
 
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      09-29-2009, 04:24 PM
I tried to report these routing problems to TT. Because they no longer have the "report map errors" menu item, I went through the Support menu to post a question from my TT account. TT's reply was "all map errors must now be reported using Mapshare".

I attempted that, but my 920 would cut me off part way through the entry. I was trying to enter...

"A route from Cascade Locks, OR, to The Dalles, OR, is routed correctly. If I do "travel via" Hood River, OR, the route remains unchanged (does NOT pass through Hood River), even though the map shows there is the little yellow flag in the center of Hood River."

I could only get about half the text entered before the 920 went to the "is this permanent", "do you want to send this" sequence. I had the same problem when I tried to enter the second statement about the Wal-mart routing problem.

Again, I asked TT via the 'questions" from my account, pointing out the difficulty of reporting these problems. Their answer was "don't worry, anything you say is enough to launch an investigation". I'm skeptical that what I was able to report via Mapshare will be of any use to them, even if they take seriously what little gets to them via Mapshare.

Is there any way to report complex issues like this to TT without using Mapshare? Or is there some way to use Mapshare that works better than I experienced?

Last edited by FlyGuy; 09-29-2009 at 04:27 PM.. Reason: spelling error
 
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      09-29-2009, 05:56 PM
Yeah, call support at 866-486-6866.
 
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      09-30-2009, 05:30 PM
My Gps TomTom Go 920T show wrong address .
I was invited to join the party dinner at Summit House restaurant 2000 E. Bastanchury Rd ,Fullerton CA 92935.
GPS Show the location off 2 miles from the restaurant.
Google Map also indicated wrong location too.

 
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