Inaccurate time estimate on 720

[huygens21]

Today I made a formal measurement for a fairly simple trip to verify a suspicion I have regarding ETA.

I made a trip in Michigan from Auburn Hills, to Mio, to Rogers City. 720 said that the trip would take 5 hours 23 minutes.

I used my stopwatch and measured 3 hours and 50 minutes.

No, I did not speed. I stopped for a 10 minute break twice -- so I should have been 20 minutes late. In other words, without stopping I should have made the trip in 3 hours 30 minutes.

Maybe most of you feel that this error in calculation is negligable. I wish it was a more useful feature for announcing ETA.

 

[RogerD]

I've been doing a lot of distance driving with Nav6 on my Treo. The estimate is always way off until I get close to my destination. Even then, traffic, bio breaks, side excurisions will always affect the results. Also, it's not possible for them to accurately calculate all the different driving speeds along the route. Especially when some small town decides to have a speed trap for a mile or two along a 70 MPH stretch.

I have disabled the "arrive by" feature and just use the ETA when I'm within an hour or so from my destination. I must say I'm impressed with the speed/frequency of recalculations done by TT. It's obvious they aren't just computing the expected results at the beginning of the trip and then counting down.

 

[wimac75]

ETA is off and Tomtom is aware

The ETA is off--way off in fact. I had a Garmin and a TomTom in the same vehicle. The Garmin calculated the trip at 3hr 32min and the TomTom calculated the very same trip/same route at 5hr 15min. It seems it always estimates about 40% more than it actually takes. In reading reviews on the net this has been an issue with Tomtom for quite some time.

I don't think the feature is negligable--I think it's important and very useful. "Where you at, how long until you get here?" "I'll be there at 7:25pm." It's nice to know.

I contacted Tomtom tonight about the issue as I was contemplating returning the unit. They said it's a known issue and they are getting a lot of calls. It does seem that their focus tends to be in the UK rather than in the US and they release many more updates for the UK software.

 

[Buddharay]

I've heard of a couple other people saying they estimate a little on the higher side, but I have to say I don't see it on my XL. It may be because I have it set so it tells me my estimated time remaining. I have found that to be pretty accurate instead of the just looking at the estimated trip time at the very beginning of the ride. I'm sure the accuracy depends on how far the trip is and the type of roads your on (interstates, two lane hwy, etc.) but I feel my ONE XL has been pretty good. I used it on a trip from DC to the Outer Banks NC a few weeks ago and it was spot on (minus the traffic I hit near Norfolk )

 

[uocooper]

I don't have a Garmin but since they use the same Navteq data that Google maps uses I believe this should be a valid comparison. If you use Google maps you can right click to mark points on the map as the start and end points and it will show those points using their longitude and latitude. The first test I performed was a roughly 40 mile stretch of Interstate 5 with no cities or towns in between. On the TomTom this is categorized to as a motorway. I then took the longitude and latitude values and used them to perform an advanced planning route on my 720. I was then able to calculate the speed from the distance and length of time given from Google and the 720. Just because I don't trust my own math I used this site- http://www.csgnetwork.com/csgtsd.html The results:

Google- 66 mph
720- 61 mph

The next test was a stretch of US Highway 26 which is categorized as a major/international road. Again the stretch of highway had no towns or cities in between and was about 40 miles long.

Google- 52 mph
720- 40 mph. Wow, that's not even close.

As you can see this is a significant difference that can really add up to huge variances in the ETA's provided. The longer the trip, the more the ETA's will differ.

We should push them to come up with a fix. One thing I can say about Tomtom is that if they get enough feedback from their customers on a specific issue they do have a history of making things right. I don't know if it could be resolved via a Map Share update or a patch to Navcore but it does seem that something needs to be done to fix the ETA estimates. Nothing will happen if we don't take the time to call them about this so please take the time to let them know that this is something that needs to be addressed. 1-866-486-6866

 

[digital-flex]

I don't have a Garmin but since they use the same Navteq data that Google maps uses I believe this should be a valid comparison. If you use Google maps you can right click to mark points on the map as the start and end points and it will show those points using their longitude and latitude. The first test I performed was a roughly 40 mile stretch of Interstate 5 with no cities or towns in between. On the TomTom this is categorized to as a motorway. I then took the longitude and latitude values and used them to perform an advanced planning route on my 720. I was then able to calculate the speed from the distance and length of time given from Google and the 720. Just because I don't trust my own math I used this site- http://www.csgnetwork.com/csgtsd.html The results:

Google- 66 mph
720- 61 mph

The next test was a stretch of US Highway 26 which is categorized as a major/international road. Again the stretch of highway had no towns or cities in between and was about 40 miles long.

Google- 52 mph
720- 40 mph. Wow, that's not even close.

As you can see this is a significant difference that can really add up to huge variances in the ETA's provided. The longer the trip, the more the ETA's will differ.

We should push them to come up with a fix. One thing I can say about Tomtom is that if they get enough feedback from their customers on a specific issue they do have a history of making things right. I don't know if it could be resolved via a Map Share update or a patch to Navcore but it does seem that something needs to be done to fix the ETA estimates. Nothing will happen if we don't take the time to call them about this so please take the time to let them know that this is something that needs to be addressed. 1-866-486-6866

Great post uocooper! That is a definite difference in time for ETA. I'll email support and see what they say.

 

[Pedro2NR]

Nice investigation.
Keep us posted DF.

 

[MrBeetle]

Great post uocooper! That is a definite difference in time for ETA. I'll email support and see what they say.

Here's the response I got today.

Thank you for contacting TomTom Customer Support. We would be happy to answer your questions on estimated arrival time.

The arrival times on the TomTom range of products use a complex and conservate calculation to determine arrival time. In an attempt to provide accurate and realistic arrival times the unit adds stops for gas, food, and just rest periods for longer trips. While some drivers prefer to drive a long trip straight through from point A to point B, which means they arrive sooner than the unit predicted this arrival time method has proven to be accurate for the majority of our customers. We hope that this answers your questions.

If you have any further questions or comments, please email 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,

 

[digital-flex]

I just sent my email. We'll see what they say.

 

[Balthazar_B]

Here's the response I got today.

Thank you for contacting TomTom Customer Support. We would be happy to answer your questions on estimated arrival time.

The arrival times on the TomTom range of products use a complex and conservate calculation to determine arrival time. In an attempt to provide accurate and realistic arrival times the unit adds stops for gas, food, and just rest periods for longer trips. While some drivers prefer to drive a long trip straight through from point A to point B, which means they arrive sooner than the unit predicted this arrival time method has proven to be accurate for the majority of our customers. We hope that this answers your questions.

If you have any further questions or comments, please email 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,

The obvious rejoinder is that they need to make this configurable by the user (e.g., Set NonStop/Set Leisurely). Should be a fairly simple NavCore fix.

 

[digital-flex]

I never got a response to my email yet but I expect to get the same answer as MrBeetle.

 

[uocooper]

I called the support number and just told them that I wanted to provide them with feedback about the arrival time estimates. The person I spoke to was very nice and said that the feedback would be passed along. I think the advantage of calling vs. using email is that with email they tend to assume you're doing something wrong or they just don't get it that you're trying to give them feedback and not get tech support. It would probably be a good idea to give them a call if you have them time.

I also got a survey about my experience with the phone support and at the end they ask for suggestions to improve the product. I also went in to detail about the ETA's in that section as well.

 

[thaJack]

Your issue isn't limited to the 720. I have a 720 and a 700. I've had my 700 for about two years now and use it all the time. I can say that based on my experience, the ETA is exactly what it means, an estimate... a very conservative one at that.

In town, though, it's fairly accurate. It seems to be more conservative with distance driving, though.

 

[lateknightucd]

I was given a link to this thread regarding ETA's after posting on issue in the ONE forum. I don't quite understand why TT is attempting to accurately predict how long drivers will be stopping for. I would think that they would predict only the time the car is actually on the road driving towards the destination. The email that someone got regarding ETA's seems to me to be a line of BS regarding a problem they don't want to fix. I would figure that most users would assume that a GPS unit's displayed ETA relates only to time spent driving. I'll be calling customer service today...

 

[The Spook]

I don't quite understand why TT is attempting to accurately predict how long drivers will be stopping for.

It isn't, simple as that. It assumes that you won't be stopping. If you do stop, the ETA just starts going up to account for the stop.

The email that someone got regarding ETA's seems to me to be a line of BS ...

My thoughts also. I would prefer to hear "Sorry Sir, I don't know the answer to that" than be given a load of rubbish.

 

[hc_spooky]

the response from tomtom is very bad news.

this means they do not recognize this as a problem so it is never giong to be fixed.
i'm one step closer to return my tomtom to costco. it's not the ETA, it that the unit uses the ETA to pick the fastest route. tomtom is way off picking routes where the freeway is not the fastest.

 

[hc_spooky]

check out my thread too.

https://www.tomtomforums.com/showthread.php?t=5443&page=2