major problem with routing - ETA

Discussion in 'Maps and Routing' started by hc_spooky, Dec 18, 2007.

  1. hc_spooky

    hc_spooky

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    I did my forum search. I have found similar topics, but I think this needs a new thread because this is very under-estimated problem.

    This is about the ETA problem.

    Bit of a background:
    I got my new 920 from costco.com $399+sh+tax.
    I'm a very experienced gps user. I'd had gps on Pocket PC (with routis,ostia,tomtom,destinator,mapopolis) and also had Nuvi 350, Magellan 3250. I gave this new tomtom a try.

    The major problem is how it calculates ETA.
    This is not a nice to have feature - this is the major parameter when the routing engine picks the fastest route!

    It's is very dissapointing that the unit picks usually bad routes. This is suppose to be the no#1 factor as fas as the gps routing performance goes. Having this unit - I can easily be driving the longer route spending more money and time on the trip.
    I hope this is a problem which can be fixed by firmware, but i'm not sure i'm going to wait. I'm living for now.

    still better than magellan though. magellan is so stupid that the fastest route gives later ETA than their shortest route. tomtom is at least consistent and showing later ETA for shortest route (where applicable).

    so i don't know. the unit is wonderfull, feature rich, but what is it worth when somebody having a $100 unit gets to the destination more efficiently. I should probably get some answers from tomtom tech. to see if they working on this. :(
     
    hc_spooky, Dec 18, 2007
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  2. hc_spooky

    fanchee

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    For what it's worth, I have my TomTom 720 and a Garmin 260 calculate a route and about 95% of the time, they choose the same route. But the TT is off on ETA by quite a bit. The Garmin seems dead on. But again, they both choose the same route.
     
    fanchee, Dec 18, 2007
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  3. hc_spooky

    hc_spooky

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    try this route:

    from: carson city, nv
    to : fremont, ca

    clear choice is to take HWY 88.
     
    hc_spooky, Dec 18, 2007
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  4. hc_spooky

    zerimar

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    I've not used my 910 in the US yet so I couln't confirm. I travel a lot within the EU by car and although our company cars have a built-in gps, I take my 910 with me for comparison and have both navigating to the same destination. Both have always used the exact same route which in my opinion both nav systems have always used the best setting aside traffic.
     
    zerimar, Dec 18, 2007
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  5. hc_spooky

    46jimbo

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    Not necessarily the case. The TomTom figures that a longer route on the Interstate is faster than a secondary highway like #88. And it probably is! And perhaps a safer drive too!

    These navigators are only tools. You can't expect them to have the knowledge of a local person. What's the best way to go from A to B? Locals may give you 5 different answers. You can always change the routing if you think you know better.

    If you are in totally strange territory, believe me, you are just happy to arrive! Even if a local wouldn't have taken that particular route.
     
    46jimbo, Dec 18, 2007
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  6. hc_spooky

    ruwafl

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    +1 what 46jimbo said. the eta on my tt1 is usually pretty accurate. it changes as you actually start to drive the route. as far as routing goes, if i am going somewhere i have not been before and am depending on tomtom to get me there, i will look over the route it picks for me. that way i can make changes if i need too. make an itinerary route out of it that goes the way you prefer. you can also have it pick an alternate route for you that you may like better. that way you always have a choice.
     
    ruwafl, Dec 19, 2007
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  7. hc_spooky

    hc_spooky

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    thanks for reponses.

    not in this case the freeway is not a faster route. using hwy 88 is 4h. using freeway 80 is 4:30h. both going within speedlimits. google, mapquest and all others i've tried (except magellan) picks not the freeway.

    since when is the road safety a parameter of picking the fastest route ? ro any route.

    what i'm in a total strange teritory that's when i need to rely on good routing. be sure not wasting 1/2h here and there. i can pick freeways using the any maps picked up on the gas station.
     
    hc_spooky, Dec 19, 2007
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  8. hc_spooky

    46jimbo

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    Apparently there is something in the routing 'logic' that tries to minimize left-hand turns. This is perhaps why you don't get the same route when you do it in the opposite direction.
     
    46jimbo, Dec 19, 2007
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  9. hc_spooky

    Mike28a

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    different routes for the same pathway, FM traffic

    I noticed this morning that my trip to home from work and vice versa are completely different, one using I-95 from Baltimore to College Park and the reverse using the B-W Parkway. Left turns? I have to think about that. The time is almost identical, as I have used both. No GPS is going to know the truly best way based on conditions that you regularly use. I use the FM traffic receiver to help me avoid the big messes though. It saved me an hour delay the first week, almost paying for itself right there.

    Now, if only I knew the best stations to tune in manually ...

    Mike
     
    Mike28a, Dec 19, 2007
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  10. hc_spooky

    hc_spooky

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    i understand a gps cannot pick always the best route because there are so many factors - lights, trucks, etc...

    but 4:30h or 4h is signifficant IMHO.

    another major thing I did find this morning (maybe this need a new thread too):

    so there's street where you can't do U-turns no turh to left (divided by curb). tomtom navigates you to the destination on the wrong side of the road. then you have to figure out the way on your own how to get on the others side, drive around and get back. not cool.
     
    hc_spooky, Dec 19, 2007
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  11. hc_spooky

    hc_spooky

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    to 46jimbo:
    you have also forgot the fact the you need gps navigation when you do not know the route. don't you want the unit which takes tou there in the fastest time ? isn't the least time spent on roads the safest route ?
    and remember i'm not talking about the shortest route at all. it's all about the fastest.
     
    hc_spooky, Dec 20, 2007
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  12. hc_spooky

    hc_spooky

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    i just got this response from TOMTOM:


    Thank you for contacting TomTom Support. We appreciate the time you have taken to contact us regarding to route planning with your TomTom GO 920. Our goal is to provide you with exceptional customer service, and we are happy to help.

    Upon review of the information provided, we apologize for the inconvenience and frustration this has caused. The TomTom device uses Route Planning Preferences to determine the best safest route to use. You do have the option to change the Route Planning Preferences, so the device does not plan to one specific type of route. If your TomTom is constantly routes to freeways, we suggest changing the route Planning Preferences on the device. To check the setup for Route Planning Preferences, please use the steps below.

    - Tap on the main driving view screen to enter the Main Menu.

    - Tap on Change Preferences.

    - Tap on the arrow to page 5

    - Tap on the Icon for Planning Preferences

    - We recommend selecting the preference "Ask me every time I plan".

    Each time you enter a destination, the TomTom GO 920 will ask what type of route you want planned. If there is a freeway involved, the TomTom will ask if you want to avoid freeways. If you say 'yes' to avoid freeways, the device will plan the route not using freeways. If you say 'no', the route may include traveling on freeways.

    We recommend the only time to use the 'shortest route' option, when walking, driving a bicycle, or for short distances in busy cities where your driving speed remains relatively constant. If this option is selected for long distance type driving it may literally take you hours more travel time to save a few miles in distance.

    The Estimate Time of Arrival is based of many different factors. The estimate time of arrival is base on travel speed to travel conditions.

    If you have any further questions or comments, please e-mail or call us at 866-486-6866 Monday through Friday, 8:30 AM until 7:00 PM EST. Thanks again for writing. At TomTom we believe in showing you the way the easy way.

    With Best Regards,

    Ruselle
    and
    The TomTom Customer Support Team

    Here was my question:
    Customer 12/19/2007 06:55 PM
    Hi,
    I purchased the Tomtom 920.
    The Routes this unit calculates are far from fastest routes available.
    It tries to route too aggressively to freeways.
    Example: Carson City, NV -> Fremont, CA.
    ETA calculations are also very bad.

    Does Tomtom recognizes this as a problem ? Are you working on a FIX ?

    I'm not going to be more detailed here. There are tons of complaints about this on tomtom related web forums.

    If your answer is going to be some generic copy/paste reply or advising to use alternate route calculation on the unit, that will indicate you are not recognizing this to be a problem.

    Being able to calculate the fastest route is the top priority in a gps unit. Your answer decides if I shall wait for a fix or return in to the store.


    thank you.
     
    hc_spooky, Dec 20, 2007
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  13. hc_spooky

    hc_spooky

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    this indicates TOMTOM is not recognizing this a a problem. and are not working on this at all.
     
    hc_spooky, Dec 20, 2007
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  14. hc_spooky

    mcaswell

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    Probably... I think there is a reluctance for them to acknowledge that their product is not 100% perfect. But that's nothing new... how many times, with other products (not just GPS) has there been some significant problem that is causing a HUGE stir on discussion forums, and when all these people call the manufacturer, they get the same answer... "gee, that's the first we've heard of this problem."

    But in this particular case, it could be something else. Apparently, when TomTom support (and most other big companies) receives email, they don't actually read the entire message, contemplate the meaning, and compose a real reply. Instead, they glance at it, see the message is about route planning, and hit a button to fire off the standard "here's how to set your routing preferences" reply.

    This is quite sad, because here you are, a customer taking the time to point out a major problem, and you end up feeling as though you've been brushed off.

    Anyway, I'm having the same problem with ETAs... the calculation for Interstate routes is close enough, but is WAY off for highway travel (estimates 3 hours for a 2 hour drive). Realizing that emailing TomTom support was a dead-end, I reported the error on the TeleAtlas website (don't know the URL right off the top of my head, but on their error-reporting page, they did allow me to specify "ETA calculation is too long for this road" or something like that), and on the TomTom unit itself with MapShare.

    --Michael
     
    mcaswell, Dec 22, 2007
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  15. hc_spooky

    DocChemRock

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    Location:
    New Jersey
    TomTom Model(s):
    One
    Try Shortest Route and you'll get HWY 88.

    TomTom's routing engine puts to much weight on the use of interstates. In fact, if the road you prefer parallels an interstate the routing engine will continuously try to put you on it (you need to block it). In NJ the turnpike (toll road, 65 MPH limit) parallels 295 (free, 65MPH limit, in most parts) unless you block toll roads or the turnpike TomTom will take you out of the way to get on the turnpike (so does Garmin).

    In countries where interstates (autobahn) have unrestricted speed limits this may be an advantage (in most cases the distance travelled is too short to actually impact the arrival time). Think about it, If your total distance is 70 miles and you travel at 70MPH verses 60MPH the time savings is 10 minutes. How fast would you have to travel to save 10 minutes off a typical 30 mile trip?

    In the USA where secondary roads have the same speed limit as interstates the added distance only adds time. The added distance to get on the interstate simply adds time.

    If you notice, when you select shortest distance your unit now warns it is not the "Safest" route. So to further weight the use of interstates TomTom now includes a "safety factor".

    Enough rant. With the increased popularity of GPS systems the routing engines should be taking leaps forward as the demand from consumers will drown out the bean counters in the corporate office!
     
    DocChemRock, Dec 22, 2007
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  16. hc_spooky

    joey301

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    Location:
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    time estimates

    How is the TT determining destination time in the first place, since it has no idea how fast I will drive? Does it take a constant average speed once you start driving, or does it know the speed limits on the route you pick?

    j
     
    joey301, Dec 23, 2007
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  17. hc_spooky

    hc_spooky

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    docchemrock:
    should i try shortest route ? what's your point ?

    I never cared about shortest route. never will. i choose always the fastest. well, whatever, i'm going to repeat myself.

    oh, yes tomtom knows the fastest route if you tell him which one is it. ok great. good gps unit.
     
    hc_spooky, Dec 23, 2007
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  18. hc_spooky

    KenM

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    Related to this discussion, I have recently taken a couple of trips through Nevada, Utah, Montana, and Wyoming. Much of the travel was not via an Interstate, and the estimated times were off drastically. I believe that TT is using a speed limit of 55 mph (or less), while many of these areas now have speed limits of 65 mph or higher (75). With the distances travelled in these states, that can be significant. TT seems to have the speed limits on the Interstates correct, and thus these calculations are correct. In at least one instance, I believe it routed me to the Interstate for this reason (shortest time routing). I have asked TT if this is going to be updated, but have not heard anything.

    Is there a way to update this myself if I know what my drive speed will be?
    Thanks
     
    KenM, Jul 26, 2008
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  19. hc_spooky

    Gilbert

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    You did not mention which map version is on your TT or T model you use which can have an effect on the answer. TT is getting there gradually. Starting with map version 7.15, it started putting speed limits on most highways and started gathering data on actual speed for use in IQ routing. With the latest NavCore v8.1, one can correct the speed limits thru MapShare. In older maps TT had three basic road speeds and calculated ETA based on this situation which was more of a guesstimate than anything.

    I regard the ETA more as a rough idea as there are so many variables as I will never rely on such information. A road is closed, an accident during rush hour, heavy fog, rain or snow and all those things that always happen when you need to rush to your destination...
     
    Gilbert, Jul 27, 2008
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  20. hc_spooky

    sab

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    I keep reading about how off the TomTom ETA is but I must say that during my trip from Montreal to Disney World which was broken up into two 12 hour days of driving, it was very close in it's estimate.

    It may have been by chance of course but I noticed that the predicition was very good with the stops included during the route. What I mean is it gave me an arrival time of 7 pm to our first night hotel and after all the driving and food/gas stops we actually did arrive at around 7:20 pm which is pretty close for such a long distance.

    This was the same for both days of travel. Again it may have been luck.
     
    sab, Jul 27, 2008
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