major problem with routing - ETA

[Arno]

I too find that the ETA on my 930 8.0.10/805 is reasonably accurate here in Toronto.
I found it pretty good in the UK, where the day of week IQ question made a lot of difference.
On long distance routes I found it to be conservative but the somewhat higher than posted speeds made up for the stops on the highway for a reasonably exact arrival.

I had a lot of destinations in my personal POI but made quite a few changes on the spot.
I have since changed to have "ask me every time" as I had a few unusual happenings.
Going from north of Dublin to Tipperary with fastest route set I did not want to go through the toll EUR 12 Dublin Port tunnel and set it for no toll roads. After a few exits on the M50, skirting Dublin, 'Jane' tried to get me to take every exit coming, which of course I ignored. Went past another exit, got a bing and a flashing sign, Toll ahead. I had forgotten from four years back that there was a toll plaza.

Another time, with friends, we wanted to drive along the shore so I set it for no Motorways. When we got to their place I just put 'Jane' in the glove box.
Next day when we were going to our next destination I was annoyed that she "missed" the direction to the motorway ramp.

Well, now it is strictly ask me any time. That takes less time than a miss.

 

[KenM]

Sorry for not providing all of my information. I have a 720 App v 8.010 with North America 2Gb map v710.1584. I too use the ETA data for reference only, especially on these long trips. (On long desolate rural roads in the west, I have occasionally exceeded the speed limit

 

[Bama Rambler]

I have an opinion about this. If you look back through the posts in this thread and at some of the issues in other threads a common theme emerges.

You notice that our brothers to the north don't seem to have the issues that we here in the "American" world do. Where am I going with this??? Unless I'm mistaken, they use the metric system up there. You'll also note that TT is a "metric" standard company.

If you remember when they (TT) came out with firmware 8.010 and allowed us to enter the speed limits ourselves there are several speeds that will not enter correctly (45mph entered will show up as 44mph on the unit, etc) I believe, through some testing, that this is a conversion issue with TT. I believe that once we enter the units in mph the TT converts it to metric and then converts it back to mph and in doinig so rounds and truncates the number so it's displayed incorrectly. There are issues with addresses being shown way off too. I did some calculations and it appears to be related to a conversion issue.

Do you suppose that our ETA's being so far off could be related to a conversion issue as well??? Oh well, enough of my ramblings.

 

[madkiwi]

We drove from Missoula, MT to Kalispell last weekend.

Our 920 informed us that the travel time was 3 hours 46 minutes (136 miles! I suppose it believed 36mph would be a good average). When we arrived 2 hours 40 minutes later my wife commented "How much did you pay for that useless thing?"

I only had one answer for her- "Too much."

For a stretch we had to go 25mph because of road construction- maybe 10 miles. The rest of the time the speed limit was 70mph- and we were doing it or close to it. We stopped a few times, but still the estimate was 40% over the actual arrival time. That is pretty bad.

We did not deviate from the route selected by the 920, by default I have it select fastest route.

 

[Arno]

You notice that our brothers to the north don't seem to have the issues that we here in the "American" world do. Where am I going with this??? Unless I'm mistaken, they use the metric system up there. You'll also note that TT is a "metric" standard company.

If you remember when they (TT) came out with firmware 8.010 and allowed us to enter the speed limits ourselves there are several speeds that will not enter correctly (45mph entered will show up as 44mph on the unit, etc) I believe, through some testing, that this is a conversion issue with TT.

Very doubtful. I was amazed that this so called metric company gives us early warnings on the freeways at 1.6 km (9 m or 3o ft short of a mile), regular announcements at 800 m (1/2 mile).
On 50 km/h streets it calls out 200 m (660 ft) for a distance of about 120 m (400 ft).

 

[Bama Rambler]

Sounds like some really screwed up algorythms on voth sides of the border. I wonder if it's any better on the other side of the pond? I keep hoping TT starts getting things straightened out soon.

 

[Arno]

Sounds like some really screwed up algorythms on both sides of the border. I wonder if it's any better on the other side of the pond? I keep hoping TT starts getting things straightened out soon.

In the 3,250 miles I just drove in England, Wales and Eire I found 'Jane' to be excellent, except for the excessive distance call out at lower speeds. (It may be the same at higher speeds but at 80 mph in a strange area I do not have a good judgment over that distance.)

Incidentally, driving home last night from the party, SWMBO was very pleased with the early call out of turns and display of distance before turns. I had set 'Jane' for "No motorways" and "Fastest route".

 

[KenM]

We drove from Missoula, MT to Kalispell last weekend.

Our 920 informed us that the travel time was 3 hours 46 minutes (136 miles! I suppose it believed 36mph would be a good average). When we arrived 2 hours 40 minutes later my wife commented "How much did you pay for that useless thing?"

I only had one answer for her- "Too much."

For a stretch we had to go 25mph because of road construction- maybe 10 miles. The rest of the time the speed limit was 70mph- and we were doing it or close to it. We stopped a few times, but still the estimate was 40% over the actual arrival time. That is pretty bad.

We did not deviate from the route selected by the 920, by default I have it select fastest route.

This is exactly the type and magnitude of error that I saw in MT, WY, and UT. I do not believe it is a conversion problem, but an issue with speed limits. I contacted TT support on this and their response was "map errors can be reported using MapShare". I believe that the speed limit being used for calculations is not more than 55 mph or probably 45 mph (or lower). I am not sure exactly why. It was very accurate in Yellowstone and Grand Teton, which does have a speed limit of 45 mph. With this knowledge, I can make the time adjustments my self. The main reason I made my post is so that others are aware of it as well. This is certainly not a major problem for me. I am going to report map errors on the roads I am aware of. (Although, being familiar with most of these, I do not need the TT

 

[Bama Rambler]

You may be correct. TT may assign a very low speed limit to a road that they don't have speed limits for. I notice that since I've downloaded firmware 8.010 there are a lot of roads that they don't show speed limits for. I enter them on all the roads that I drive where they're not shown. I hope everyone else is also because in the end we're the ones to benefit.

 

[pianoCM]

I think the American should start using the SI system (metric sytem) like the rest of the world.
I've found "our" system, the mils-inch-foot-yard-mile system (for length) is ridiculous.
They should also switch the pint-quart-gallon system (for volume) too.

 

[Arno]

I think the American should start using the SI system (metric sytem) like the rest of the world.
I've found "our" system, the mils-inch-foot-yard-mile system (for length) is ridiculous.
They should also switch the pint-quart-gallon system (for volume) too.

Funny as it is, Joe Q. Public doesn't seem to be aware that anything designed at GM since 1978 has been in metric (not inch equivalents).
Also since about 4 - 5 years, anyone wanting to sell something to the US Government (or federally subsidised programmes) must quote in SI dimensions although Imperial measurements may be given too.

I am fluently bilingual in inch/metric but around the house, because everything is based on historical units, I too prefer the comfortable sloppyness of inches and feet (never could get used to it that the US and the UK use different ounces).

 

[Gilbert]

I think you are betraying your age Arno... I'm also amazed how building material is still quite oriented in feet, inches and gallons. I don't see 4x8x5/8 gypsum boards changed to full metric equivalents or 2x4x8 wood or paint containers. After close to 40 years of having offically adopted the metric system, Canada still uses English or American measures for a lot of items.

 

[Bama Rambler]

I think the American should start using the SI system (metric sytem) like the rest of the world.
I've found "our" system, the mils-inch-foot-yard-mile system (for length) is ridiculous.

I've been saying this for 30 years.
The biggest mistake we made is trying to have both and gradually switch to metric. We should have picked a day and said "on this day everything will be metric" and stuck to it. People hate change even if it's good for them.

 

[Arno]

I'm also amazed how building material is still quite oriented in feet, inches and gallons. I don't see 4x8x5/8 gypsum boards changed to full metric equivalents or 2x4x8 wood or paint containers. After close to 40 years of having offically adopted the metric system, Canada still uses English or American measures for a lot of items.

Gilbert,
The real galling part is that the paint distributors switched from our Imperial 4.546 litre to the Yankee 3.785 litre gallon and, in the process, increasing the price on top of reducing that volume!
Arno

 

[Gilbert]

Gilbert,
The real galling part is that the paint distributors switched from our Imperial 4.546 litre to the Yankee 3.785 litre gallon and, in the process, increasing the price on top of reducing that volume!
Arno

That's what they call ?NEW and improved!?. Even the larger ?contractor? paint containers from Canadian companies have those odd metric sizes that translate to even numbered US gallons. Even after all these years, when I think of people's height, I still think in ft and inches. Can't relate to 1,75m, I need to convert to ft and inches but this 2,54cm to the inch has my mental math often challenged...

 

[Viventis]

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.

I almost didn't buy the 720 because one review blasted the Tomtom for picking slower routes than two competitors based on the ETA's. I tend to believe that the Tomtom picks it's routes very well, but the ETA's, when compared to other brands, makes it look bad. In the week that I have had my 720, it always over-estimates arrival, even if I drive the speed limit.

 

[dhn]

Yeah, but it's fun (in a way) to see it correcting itself dynamically as you drive your route.