Nav vs BC timing difference

[Fxwheels]

I probably didn't pay attention to it before, but lately I've discovered that the Basecamp route travel time is not the same after loading to the nav by a big margin. For example on a 4-5h ride, BC time can be one or more hour longer (give or take depending on route). Distance just 2 to 5 miles off, but that's fine. I checked all settings in BC and navs for avoidances. I also have Fastest time in both.
I've checked-marked the "Always match route to the map on my device when transferring" in Edit/Options/Device Transfer, but the time got even by 30 min longer.
Have tried that on the XT and 396 and the results are the same.

Have you checked your travel time in BC versus the nav time?

[jfheath]

It sounds like your XT is recalculating the route. The XT doesn't use FASTEST time. It uses FASTER time - a pedantic difference in terminology which gives it a lot of leeway in how it achieves that. The XT likes to head for the major roads, even if it takes a lot longer to to get to the destination. It is still faster than taking the twisty turny backroads. Maybe. This is very different behaviour from previous Zumos like the 595.

I recommend turning off all of those checkboxes in Edit / Options / Device Transfer, and click the button to apply those settings to all of your devices. Make sure that you have identical maps on Basecamp and the XT. Never upgrade the maps on the XT without updating those on Basecamp at the same time. And if you load an old route, make sure that you recalculate it in Basecamp, before transferring.

If the route is taking a long time to import on the XT - say more than a few seconds - then the route is being recalculated, and something is wrong. The screen will always show the message that it is calculating, but that may be just normal processing. When a route is imported, it had to pick out any saved waypoints and place them in Favourites, and it has to work out the time calculations. But this doesn't take much more than 5 seconds.

But if the route hadn't changed, then the timings should be very similar. Not the same, 'cos your Xt will take into account any traffic info that it has discovered.

To get round the issue with heading for faster roads, then you get used to spotting these in the same way that you would when planning a route to avoid motorways. That is the careful use of shaping points. Typically, if I want a route along the A6 rather than the parallel Motorway M6, this can be achieved by putting a single shaping point in the middle of the A6. But motorways are ine way streets. To use the fictitious B6123 instead of the parallel A6, I may need two or more shaping points spaced at one third intervals so that it is not tempted to visit the shaping point and then u turn back to the A6.

In Basecamp, I have all of the route avoidances unticked. I have all of the avoidances in the XT unticked. None if that info from Basecamp is transferred to the XT except the vehicle Motorcycle / Driving and the Faster Time / Shorter Distance. Anything else the XT defaults to using Faster / Motorcycle. But Basecamp sends all if the invisible routing points to the XT along with your shaping, via, and saved way points.

Providing the XT isn't allowed to recalculate, then your Basecamp route will remain intact. The timings should be more or less the same.
However, the XT uses your vey recent riding in order to work out times. So if for example, if the last time you were out on a 60mph road, traffic dictated that you could only manage 30mph, I could see how this would affect its calculation for a route with a lot if 60mph roads in it. As soon as you have been riding on open roads again, I think those times will adjust on the XT.

[colirv]

However, the XT uses your vey recent riding in order to work out times.

Now that I didn't know!

[danham]

In addition to jfheath's excellent explanation, two more thoughts. First, he is correct that many Garmin GPS models "learn" your riding habits. They do this by comparing three variables: the road classification (what speed it was built to accommodate), the posted speed limit, and the speed you drive. If I routinely exceed the first two, the XT takes that into account when predicting an ETA.

Second, in Basecamp you can set a preference to add speed when estimating route travel times, so moving the slider will bring it a little closer to the XT's estimate. I have mine set in Routing --> Custom Speed to add 6 mph. That seems to fit my needs; your mileage may vary, as they say.

But as mentioned, none of this works properly if you let the route get recalculated during transfer.

-dan

[jfheath]

The XT and some earlier models also build up a profile of which roads you like to ride. So if it spots you are heading in the same direction again, it will choose to route you along a road that you have taken before. (I Know that the 590 and 595 would do this).
There is a section in the Systems Diagonostic page (View Map->Speedo->long press the circular speedo -10sec)
Developer Info -> MyTrends Info. History and Routes both reveal some intersting info about your riding.

I wonder just how useful the observation that I "Routed to Unknown at 16:41 1 time(s)". I wonder if that is why it keeps routing me to other unknown places ? No maybe not !

[Fxwheels]

In Basecamp, I have all of the route avoidances unticked. I have all of the avoidances in the XT unticked.

I have it all unchecked with exception of Avoid unpaved in BC and XT (some touring bikes riders in the group bashed me for that more then ones when I intentionally or unintentionally took them on these).

However, the XT uses your vey recent riding in order to work out times. So if for example, if the last time you were out on a 60mph road, traffic dictated that you could only manage 30mph, I could see how this would affect its calculation for a route with a lot if 60mph roads in it. As soon as you have been riding on open roads again, I think those times will adjust on the XT.

As a rule I always do 5-7 over on local and 10-15 on a motorways providing if traffic lets.

In addition to jfheath's excellent explanation, two more thoughts. First, he is correct that many Garmin GPS models "learn" your riding habits. They do this by comparing three variables: the road classification (what speed it was built to accommodate), the posted speed limit, and the speed you drive. If I routinely exceed the first two, the XT takes that into account when predicting an ETA.

Second, in Basecamp you can set a preference to add speed when estimating route travel times, so moving the slider will bring it a little closer to the XT's estimate. I have mine set in Routing --> Custom Speed to add 6 mph. That seems to fit my needs; your mileage may vary, as they say.

But as mentioned, none of this works properly if you let the route get recalculated during transfer.

-dan

I really don't like this "learn riding habit" by the nav. The riding is varies great deal depending on different situations and I'd prefer if the XT was using the speed limit initially and then readjust timing as I go based on conditions (which it does anyway).

I also do set a preference to add speed in Basecamp. About 5 to 10 more depending on road (local, highway, etc.)

[jfheath]

You can delete the travel history, but it also clears the active logs from CurrentTrackLog.gpx and all of the previous track logs in Archive. If you want these, transfer them to your computer before clearing the travel history.

The option is available from the Track app. Click the track icon and then the calculator type tab, and then the spanner.

[Fxwheels]

So I think I've made all the right settings, yet a new route I made is still shows about 30 min less on the nav than in the Basecamp.
I don't know how or if I can upload the gpx file here, but here is the google link. Interestingly enough Google maps shows 5h 3min, Basecamp shows 4h 1m, and the XT shows 3h 36min
https://goo.gl/maps/z8rymfSYUcYZTSCU6

[Peobody]

@Fxwheels, my experience with BC times is much the same as yours, in that it is almost always more than what the XT shows. I also believe that most of the routes I create in BC are calculated by my XT on import. I have followed the advice here on both issues but haven't resolved either (I have increase the BC speeds by 5 mph). A ride I took two days ago is similar to your experience in that BC showed the route time at just under 4 hrs whereas the XT showed it 28 minutes less. The XT was closest to actual ride time. My experience when long distance touring is different. I plan 6 hr/day routes in BC and usually reach destination at around 8 hrs. That includes a lunch and a fuel stop, and usually one other stop (can't pass up a cool looking donut shop at 10:00 am). I do not include layover times in any waypoints when planning in BC. BC times are solely saddle time.

[Fxwheels]

@Fxwheels, my experience with BC times is much the same as yours, in that it is almost always more than what the XT shows. I also believe that most of the routes I create in BC are calculated by my XT on import. I have followed the advice here on both issues but haven't resolved either (I have increase the BC speeds by 5 mph). A ride I took two days ago is similar to your experience in that BC showed the route time at just under 4 hrs whereas the XT showed it 28 minutes less. The XT was closest to actual ride time. My experience when long distance touring is different. I plan 6 hr/day routes in BC and usually reach destination at around 8 hrs. That includes a lunch and a fuel stop, and usually one other stop (can't pass up a cool looking donut shop at 10:00 am). I do not include layover times in any waypoints when planning in BC. BC times are solely saddle time.

Yeah, if to count the ride time only, it is close to nav time and not the BC time. I've experimented with 2 more gps's (my 396 and friend's another XT) and the timing is the same. It still beats me why BC shows slower time, and it is misleading when planning, but I will take the nav time into consideration after uploading the route.