Estimated travel times way off

[Lauranda]

I just drove 1000 miles (mostly on interstates) and the estimated time calculated out as if I was on 50 mph roads the entire time, which is way off. What may be the reason for this?

 

[tukatz]

I just drove 1000 miles (mostly on interstates) and the estimated time calculated out as if I was on 50 mph roads the entire time, which is way off. What may be the reason for this?

I experienced the same thing with my Go 700 and the original maps. When I got upgraded maps (710.1609) I found that the estimated times were much more accurate. Incidentally, we traveled in Europe with our 910 this past summer and the map data there is much better and more complete. The estimated times there were very accurate.

 

[gpstrucker]

Could be that part or all of your route simply didn't have enough historical data for IQ Routes to calculate the correct speed/time.

I've noticed that in certain states the trip time calculation is pretty accurate, where in other states it can be much longer than the actual time. I'd say the lack of IQ Route data accounts for that.

 

[dhn]

For North American maps at level 7x, TomTom's ETA calculations are based on only 3 types of roads and default speeds for those roads (freeway, main road and, I think, street). Each has a different default speed embedded. (European maps have 7 types of roads, each with its own default speed; consequently, European eta's are more precise --- as was pointed out).

For version 8 maps (and firmware 8x), there is IQ routing available for NA maps. The theory is that more precise speeds associated with roads will result in more realistic eta's in v8 maps.

The drawback at this point is still a scarcity of valid IQ info for many North American roads; hopefully, each map update will result in more data for IQ routing to work better --- and more accurate eta's.

 

[rcacs]

Yes, I too have found that feature to be completely useless as well. Using both the Time Remaining and initially Time to destination are so far off that they are of no value at all. It seems to only "catch up" when you are about 5 mins from your destination.

Also, if you check your trip statisics, the distance to Home is always way off too. I could go say...100km straightaways from home, and the distance recorded back to home is always about 30% out.

cheers

 

[GAW]

Yes, I too have found that feature to be completely useless as well. Using both the Time Remaining and initially Time to destination are so far off that they are of no value at all. It seems to only "catch up" when you are about 5 mins from your destination.

Also, if you check your trip statisics, the distance to Home is always way off too. I could go say...100km straightaways from home, and the distance recorded back to home is always about 30% out.

cheers

The longer time without IQ routing are the nature of the beast. of course they get beter the closer you get - there is less ground left to cover.

i am surprised at the millage though - I have compared to after-the-fact odometer readings and Map Quest estimates before the fact and have found the mileages to be generally consistent.

 

[rcacs]

The longer time without IQ routing are the nature of the beast. of course they get beter the closer you get - there is less ground left to cover.

i am surprised at the millage though - I have compared to after-the-fact odometer readings and Map Quest estimates before the fact and have found the mileages to be generally consistent.

The actual mileage compiled is correct. It is on the "Trip Statistics" screen that the distance to your home is way out. The mileage you have actually completed seems to be precise.

Cheers

 

[cputrdoc]

Haven't seen it recently but I used to see insanely high estimated travel times. I never caught it in the act but it was as if the speed limit on a portion of road was about 0.1 mph. A 2-hour trip would be estimated at 7+ hours; once I was past a certain point in the trip it would acknowledge I truly had only 20 minutes left. I should add that up until a certain point, the time progression en route was accurate. After one hour, it said I only had about 6 hours left of driving. Then I would look down and see it had dramatically revised the estimate somewhere along the route.

Anyone else see this?

 

[rcacs]

I dont even use that feature on the main screen anymore. Just too useless when I am going an average speed of say 110kph, the distance to my destination is say 75km, but the Time to Destination is telling me its going to take 3.5hrs......

Cheers

 

[Old Baldy]

I've always found my TT1 ETA to be amazingly accurate over the long haul, provided one takes short breaks every couple of hours to fill up and grab a bite to eat. Over a distance of over 1000 miles, it's been accurate to literally within a few minutes of the original ETA time. BTW, it certainly seems MUCH more accurate than my wife's Garmin C580 over ANY distances, in my experience.

On short trips up in the Detroit metro area, it's very accurate, provided it does not attempt to route me such that I won't do a left turn at my destination, as we all know it tends to attempt to prevent us doing.

Perhaps the degree of accuracy is area specific?

 

[dhn]

Baldy...

Think you'll find the combination of newer maps and newer firmware is much more flexible when it comes to the issue of making left hand turns. No more right turn, right turn, right turn sillyness for the most part.

 

[21rouge]

I have the 810 maps and the 810 firmware and I am impressed at the accuracy of the arrival time estimated by the unit. Almost spooky in its accuracy for a trip I took last weekend. I for sure was going well over the posted speed limit on a couple 400 series of hwys in Ontario and the GO730 was accurate re my arrival to within 1 minute on a trip that was about 40 miles in distance.

 

[tukatz]

You've obviously never been to New Jersey

Baldy...

Think you'll find the combination of newer maps and newer firmware is much more flexible when it comes to the issue of making left hand turns. No more right turn, right turn, right turn sillyness for the most part.

There are a number of places in New Jersey where you have to make three right turns to make a left turn. In some cases it feels like you are going through parking lots in the process. Very strange.

 

[wasdvd]

We have traveled from Florida to Maine and back, with remarkably accurate estimated times of arrival all along the way. There were a number of times that the traffic was optimal, so the times would have been off with "normal" traffic.

Version 8 maps.

 

[sageuvagony]

I haven't had to deal with traffic yet but so far my TomTom ONE XL has been pretty accurate as to my arrival time. It has been off no more than 2 minutes. The longest trip I have entered into my ONE XL so far has only been 54 miles but still has been accurate. I would assume if I were to drive during rush hour it will be off by a bit.

All this is without IQ routing or a traffic subscription.

 

[rcacs]

This all makes me wonder why my Rider2 is so far off. I tried it again yesterday, and it is just so far off that it is not a useable feature. I even stopped at one point, re-navigated to my home which was now only 54km away (about 30 miles) and it estimated my time of arrival as being not for another 1hr and 17 minutes. This was on an open rural highway, with an average speed of 110kph.

Cheers

 

[dhn]

Unless, for some reason, the map info for the rural highway is set for, say, 40 km / hour??

 

[rcacs]

Actually, it is the TCH, but in the rural setting is what I actually meant. I tried having "estimated time of arrival" and/or "time left to destination" on the screen a few times this year on cross-canada bike trips, with the same results.

Cheers