Route Shortest to Fastest

Joined
Mar 5, 2008
Messages
64
Location
Mt Dora Winter, Montreal Summer
TomTom Model(s)
GO 920T
I have searched with no luck....Help!

When I set my route for shortest, it changes to fastest on it's own. I am running North_America v810.1907 with App 8.010

It seems to do it if I miss a turn and it recalculates, BUT it also does it sometimes when I am on route.
I am not sure if it started right after I installed the new map. I had lost some functions after installing the new map, but a pin reset cured that.

Any help is appreciated.

Sidney
 
Did you set it for IQ routing? If so, I think that only works with Fastest.
 
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I believe you have the answer. I won't be able to check it until tomorrow BUT I am confident you are correct.
It seems reasonable that when I got close to the highway it recalculated the "fastest" based on IQ routes even though I selected "shortest"
IQ is now disabled until I need it again. You are a SUPER Moderator!

Thanks,
Sidney
 
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I was just reading this thread and was curious about "IQ", I always just use the fastest route and not the shortest, up here in the country where I live you have to be careful about "shortest" as you could be driving on old Stagecoach Trails, so would appreciate and explanation on this difference???:confused:
 
For North American maps, there are 3 types of roads with default speeds associated with them. I think the breakdown is something like highway @ 55 mph, main road @ 35 mph and side street @ 25 mph (or close to those speeds, anyway). So, when TT plans the fastest route, it considers how many @ 55 it can use and then how many @ 35 and finally how many @25. And it gives an ETA (estimated time of arrival) that starts out waaaay too long in most cases because people actually travel faster than the default speeds.

And, in fact, the 'shortest' route may involve more of the 35 mph roads than 55, for example. So, in miles, it may be shorter but in time, it might be longer (based on the default speeds, remember).

Well, the concept of IQ routing is that users provide feedback as to the TRUE speed they travel over the roads where TT has had the default speeds at the values I showed above. So, with IQ routing, the planned route takes into consideration the TRUE speeds for roads instead of default speeds and, consequently, is supposed to provide more meaningful routing than in the past.

And, for most users, they report that is true.

Of course, the IQ routing doesn't as yet take into consideration the time of day people travel on roads, only whether it's a weekday or weekend. So, that's a bit of a drawback so far. Presumably, future firmware/map updates will have more meaningful data to result in even better routing.

IQ routing only kicks in if the user selects 'fastest' as the choice for the route. And the eta's are more realistic than they were before.

btw, European maps have 7 types of default speeds/road types; consequently, their routing capabilities (and eta's) are more precise than we in NA have.
 
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For North American maps, there are 3 types of roads with default speeds associated with them. I think the breakdown is something like highway @ 55 mph, main road @ 35 mph and side street @ 25 mph (or close to those speeds, anyway). So, when TT plans the fastest route, it considers how many @ 55 it can use and then how many @ 35 and finally how many @25. And it gives an ETA (estimated time of arrival) that starts out waaaay too long in most cases because people actually travel faster than the default speeds.

And, in fact, the 'shortest' route may involve more of the 35 mph roads than 55, for example. So, in miles, it may be shorter but in time, it might be longer (based on the default speeds, remember).

Well, the concept of IQ routing is that users provide feedback as to the TRUE speed they travel over the roads where TT has had the default speeds at the values I showed above. So, with IQ routing, the planned route takes into consideration the TRUE speeds for roads instead of default speeds and, consequently, is supposed to provide more meaningful routing than in the past.

And, for most users, they report that is true.

Of course, the IQ routing doesn't as yet take into consideration the time of day people travel on roads, only whether it's a weekday or weekend. So, that's a bit of a drawback so far. Presumably, future firmware/map updates will have more meaningful data to result in even better routing.

IQ routing only kicks in if the user selects 'fastest' as the choice for the route. And the eta's are more realistic than they were before.

btw, European maps have 7 types of default speeds/road types; consequently, their routing capabilities (and eta's) are more precise than we in NA have.

With my 930, I have found there is a bit more to it than just those three road speeds. Some roads had a 30mph speed limit in my Tomtom(which was really 35), but the decision about what road to take seems to also be based on other factors, such as the true average speed that people can go in. If you have multiple roads that have a 55mph speed limit, the Tomtom with IQ turned on will prefer the road with less traffic(higher average speeds). I keep wondering if the speeds for different roads can get updated automatically based on reported speeds or something, because it really seems to come in handy.

Anyway, to back up the other posts, you have the chance to be stuck on local roads for a route because it really is shorter, but fastest would take you on the highway/freeway/motorway because that is the fastest route. If a route only adds half a mile to your route but saves you 30 minutes, then fastest will be better. Also, shortest doesn't take stop signs or traffic lights into account, and some difficult left hand turns will also be routed on shortest(not sure if they fixed this for IQ)....I swear, it may be LEGAL to make a left turn from some roads, but it would be stupid to do so.
 

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