Mapsource Time Diference

[GreyGoose]

I just finished doing some custom routing for an upcoming trip and found a huge descrpency between the total time listed in mapsource vs. the total time listed on my 660. One of the routes has a 1.5 hours difference (7 hours vs. 8.5). Not sure which one to believe. I have my driving speeds set up to the defaults in mapsource.

I know that these times can vary depending on number of stops etc., but when trip planning i like to know how long the custom trip is going to take and adjust accordingly. I oringinally thought that the route got changed during the transfer, but it seems to be dead on what i designed. The miles of the trip are correct on both mapsource and the 660 but the times are way off.

any ideas?

thanx

GreyGoose

 

[bramfrank]

Zumo uses adapted speeds, based as ratios of the database encoded speed limits. Mapsource uses the numbers you set in the preferences. Long rides can have large differences as a result. In my experience, you will find the navigator to be more accurate.

 

[wfooshee]

The device "learns" from your actual riding (or driving.) You see it update its arrival time constanty through the trip. If you repeat the exact same route, its initial estimate will be closer than it was the first time.

I read of one user here, I believe He Of The Astonishingly Highest Miles, who finished a trip mucho rapido to meet a deadline, and his StreetPilot was 10 or 20 % optimistic for weeks afterwards.

 

[RaYzerman19]

The Zumo recalculates the route, and you may want to re-evaluate your defaults in Mapsource, however, I would tend to believe the Zumo. However, remember your arrival time assumes you can average the speed limit (difficult) and that you never stop (impossible). In general you have to go 20% faster than the speed limit to average the speed limit.

Further potential issue. A friend of mine provided me with a route he created in Mapsource, and when I loaded it into my Zumo 550, it added 3 hours. Rather impossible, I said, and also, as we rode the route across West Virginia, some of the roads were mislocated way off to the side of where we were, and showing absolutely incorrect locations for the road............. he told me later, his wife had just bought a Nuvi, and he created the route with the software version that came with it............ I don't know more than that......

 

[GreyGoose]

The Zumo recalculates the route, and you may want to re-evaluate your defaults in Mapsource, however, I would tend to believe the Zumo. However, remember your arrival time assumes you can average the speed limit (difficult) and that you never stop (impossible). In general you have to go 20% faster than the speed limit to average the speed limit.
Further potential issue. A friend of mine provided me with a route he created in Mapsource, and when I loaded it into my Zumo 550, it added 3 hours. Rather impossible, I said, and also, as we rode the route across West Virginia, some of the roads were mislocated way off to the side of where we were, and showing absolutely incorrect locations for the road............. he told me later, his wife had just bought a Nuvi, and he created the route with the software version that came with it............ I don't know more than that......

this just sounds like a mapsource version mismatch issue. My issue is occuring when the versions are matched. When you have a version mismatch, the device should ask whether you want to recalculate or not. I think you run into a "crapshoot" either way.

This descrpency makes it difficult to do trip planning based on "saddle time". I've got a 1.5 hour descrepency in one of my routes. 7 hours of saddle time is a whole differnent ballgame vs. 8.5 (IMHO).

time will tell.

GreyGoose

 

[HaulinAshe]

Next time you go riding, look at your Average Travel Speed on your Zumo. That's a hard figure to vary and an extremely good indicator of trip time. Just divide your total miles of the route by that average speed, add any expected stop times and your going to be very close.

Another method is to use a recent route you ran. Adjust the MapSucks Average Speed value until it calculates that route to match the actual time you ran it.

You'll find that riding mostly 2-lane backroads with minimal stops, 50 mph Average Speed is a pretty darn good estimate, with 65 mph being a very common Average Travel Speed.

 

[Fred W]

As others have mentioned, the estimates that the Zumo gives you are pretty darn accurate. Mapsource does tend to be somewhat pessimistic (but you can alter your average speeds in Edit/Preferences/Routing using the Driving Speeds button) and the online mapping websites like MapQuest and GoogleMaps are very pessimistic.

The way to get these set perfectly is to go back and look at a tracklog through the various road types and set them for how you travel.

 

[RaYzerman19]

The Zumo recalculates the route, and you may want to re-evaluate your defaults in Mapsource, however, I would tend to believe the Zumo. However, remember your arrival time assumes you can average the speed limit (difficult) and that you never stop (impossible). In general you have to go 20% faster than the speed limit to average the speed limit.
Further potential issue. A friend of mine provided me with a route he created in Mapsource, and when I loaded it into my Zumo 550, it added 3 hours. Rather impossible, I said, and also, as we rode the route across West Virginia, some of the roads were mislocated way off to the side of where we were, and showing absolutely incorrect locations for the road............. he told me later, his wife had just bought a Nuvi, and he created the route with the software version that came with it............ I don't know more than that......

this just sounds like a mapsource version mismatch issue. My issue is occuring when the versions are matched. When you have a version mismatch, the device should ask whether you want to recalculate or not. I think you run into a "crapshoot" either way.

This descrpency makes it difficult to do trip planning based on "saddle time". I've got a 1.5 hour descrepency in one of my routes. 7 hours of saddle time is a whole differnent ballgame vs. 8.5 (IMHO).

time will tell.

GreyGoose

Here are my preference settings (I forget what the defaults are), and these give a pretty accurate riding time excluding stops and bad traffic. The Zumo's time of arrival is pretty close in my experience........

Interstates 67mph/108 kmh, Major highways 58/93, Other highways 45/72, Collectors 35/56, Residential 25/40

Same goes for MS Streets & Trips, with all driving speeds set to Average, it almost agrees with MapSucks and Zumo.

 

[Fred W]

Mapsource defaults are:

Interstate Highways: 67

Major Highways: 58

Other Highways: 45

Collector roads: 35

Residential Streets: 25

IOW, you have yours set to defaults.

 

[TestPilot]

Interesting discussion. I find my Zumo (550) way optimistic. It calculates the time based on maintaining the speed limit the whole journey, including through towns, etc. I have not seen it 'learning' as some people describe. I have come to completely disregard the Zumo estimated trip time.

I set my Mapsource defaults of what I know I actually achieve, and fins that really accurate, except the Zumo won't accept that, and recalculates the time.

This is the one issue that has me seriously reconsidering ever buying Garmin again. It's been an ongoing issue reported/complained about on the Zumo forums for a lond time, but Garmin really couldn't care, apparently.

 

[HaulinAshe]

Interesting discussion. I find my Zumo (550) way optimistic. It calculates the time based on maintaining the speed limit the whole journey, including through towns, etc. I have not seen it 'learning' as some people describe. I have come to completely disregard the Zumo estimated trip time.
I set my Mapsource defaults of what I know I actually achieve, and fins that really accurate, except the Zumo won't accept that, and recalculates the time.

This is the one issue that has me seriously reconsidering ever buying Garmin again. It's been an ongoing issue reported/complained about on the Zumo forums for a lond time, but Garmin really couldn't care, apparently.

Interesting... So you must do a lot of stopping and riding below the posted speed limits?

 

[TestPilot]

Interesting... So you must do a lot of stopping and riding below the posted speed limits?

Quite the opposite. When touring SW USA last year our 'usual' travelling speed was the sped limit +15 mph when alone, or 'with the traffic' when in traffic (eg - Las Vegas to LA, where we had to use I15 and were constantly in traffic travelling mostly at speed limit to sl +10). We avoided all major cities except 2 nights in LV and stops were suitably 'few and far between - Zea resorted to taking 100's of piccies from the pillion seat because she knew stopping was out of the question.

What I found very early on that the time Zumo estimated for our arrival was almost always approx 1 to 2 hours ahead of what we achieved on routes like:

Yosemite Village to Mammoth Lakes

Mammoth Lakes to LV via Death Valley

LV to Grand Canyon Village

Grand Canyon Village to Page

All of these (with the exception of the LV sections) are fairly open, with just small towns to traverse, but you still have to stop even at small town red lights, etc. And the posted limit on Tioga Pass may be 55 or 60 or whatever, but it is not reasonable to expect to maintain the speed limit constatntly on a road like that. It seemd to me that Garmin makes no allowance at all for road types, and just assumes everyone travels at max speed limit, without pause or slowing for corners, red lights, or anything.

If the 'learning your riding speed' thing was real, then after 4 to 5 days of touring I would have expected the Zumo to show some learning, and certainly after 10 days of very similar riding it should have it down pat. This wasn't my experience at all, and I learned to totally disregard the Zumo ETA.

And back here in Australia, it's just as bad.

And as I said, this is an issue that is repeated on the Zumo forums, and has been treated with disdain and arrogance by Garmin. There's 28 pages of posts related to this issue here: https://www.zumoforums.com/index.php?topic=4842.0 Not all are negative, but the overwhelming negative feedback shows this is an issue.

 

[blkredlinedrvr]

I've found that my ZUMO 550 is extremely accurate. I've found the online map sites to be very inaccurate lol.

 

[Fred W]

A couple of thoughts:

First off, the Zumo does not add in any time to the ETA to accommodate ANY stops. NO gas stops, no traffic delays, no red lights or stop signs. It assumes that you will zip along at the speed limit of the roadway and never have to let off the throttle.

Secondly, as noted above, this calculation is completely dependent on the map database having the roads you will be traveling correctly identified by type (which translates to speed limits). In addition to my Zumo I also have a nuvi 765T, which has the speed limit indicator on the lower left side of the screen. I have noticed that the device correctly displays the speed limit on major highways and roadways, but many secondary or tertiary roads the display goes blank. IOW, it doesn't know what the speed limit is. This is on City Navigator North America NT 2011.10 (the latest version maps). That database would be one good reason why there is vast disagreement as to whether the ETAs are optimistic, pessimistic or spot on.

If you read through the Zumo Forum thread (linked to above), it appears that many of the users having problems with the ETA are in the UK or ANZ. My hunch would be that whoever classified the roads in the map program for those areas was a bit more "optimistic" about speeds than the folks(s) that did the US.