Zumo User Forums

I wonder if others are seeing small routing errors in Basecamp when it routes a trip. On my last ride I saw many instances where the XT said turn left when it clearly was a right turn or do a U-turn before turning in the desired direction. Upon close examination of the route created by Basecamp (using City Navigator map 2022.2, the same as used on the XT) I see many waypoints that are incorrectly located. I have included screen shots below. Even a slight mislocation causes the XT to give the wrong instructions.

Well spotted. That is an excellent point (no pun intended).

And you are correct - the Zumo is doing exaclty the right thing. It is the point on the map that is wrongly placed.

When you create a route in Basecamp I think it is absolutely essential that you select the route in question so that the trip list of all of the route points show up. At the bottom is a tick box which is labelled 'Center on Map'. As you click on each point on the list, it places that point in the centre of the screen with the map zoomed in at its highest level. You can then see the mis-placed points that your screen shots so very clearly point out.

This is a 'feature' of Basecamp. Sometimes (nearly always in fact), the point you think you have selected is not where the point is placed. It tends to snap to some unknown location. Often you place a point with the map in low detail and zoomed out and you think you have placed it on a road. In fact it places it in the middle of a supermarket or a dogs home.

When I first create a route I just drop the points approximately now. It is rare to get a point spot on when you want to see the point in relation to the entire route, and zooming in and out and increasing/decreasing the level of detail is a pain. So they get placed almost correctly, and I know I am going to have to go through them all using the 'Center on Map' options to place them precisely.

None of those points would present serious problems when naviagting. They seem to be shaping points (although you can't always tell), so although the announcement would tell you to turn in the wrong direction, you can see where the route goes, so you just follow it. If they are shaping points, and you are still on the magenta line after the point, the Zumo will not ask you to go back to visit it.

The one to really watch out for is the point that is placed on the wrong side of a dual carriageway.

I prefer to get it right in the first place, using two hands! Zoom in to exactly where I want the via point, minus sign repeatedly with left hand to zoom out to pick up route, plus sign repeatedly to zoom back in, then click to place.

colirv wrote: ↑Tue Oct 26, 2021 8:10 am I prefer to get it right in the first place, using two hands! Zoom in to exactly where I want the via point, minus sign repeatedly with left hand to zoom out to pick up route, plus sign repeatedly to zoom back in, then click to place.

Ah - you are using the XT to enter the route ? In which case I totally agree. The original topic of the post from @jskene was related to using Basecamp - hence my answer related to Basecamp rather than to the XT.

Quote:

jskene wrote: ↑Mon Oct 25, 2021 12:00 pm I wonder if others are seeing small routing errors in Basecamp when it routes a trip.

But I find that creating routes on the XT can be a pain, with my big fingers and thumbs and the super-sensitive screen. My screen responds to my fingers before they even touch they make contact - ok with gloves on, but not sitting at home.

If I have to do it, I first create Waypoints / Favourites / Saved Locations first, and then create the route using those. I find that much easier. It is much less likely to go wrong - but if it does, it only affects the one point rather than the entire route. I've lost count of the number of times the super-sensitive screen has caused me to lose everything that I have done.

The route that Basecamp used for this route was produced in Calimoto, and was not manually entered by me. I never put a waypoint at an intersection, but instead use a point 100 feet down the road, as recommended by jfheath in one of his excellent posts on routing with Basecamp.

I normally use Calimoto for route design as it's good at finding the curviest roads from A to B. I downloaded a GPX file of the route I created from the Calimoto website and imported it into Basecamp. I then asked Basecamp to recalculate the route using the latest North America 2022.2 map.

I expected Basecamp to recreate the same route using its own map. It seems that it does not use jfheath's method, but instead favors putting waypoints very close to intersections, without any sense on where the route is going. It's possible that the misrouting may result from small differences in latitude and longitude coordinates between the Calimoto and Garmin maps. I'm surprised that Basecamp doesn't consider this and compensate for it by ensuring that the route always goes in the desired direction. Maybe I need to use OSM maps in Basecamp and the XT to eliminate this problem.

I carried out a test a few years ago, taking a track of a route produced on Basecamp maps and superimposing it on a track produced for the same roads using Google maps.

The differences were small, but I felt that they were significant ie in places one track from one map did was not on the road of the other map. I have a screen shot somehwere of the test that I did. I need to look a bit harder, 'cos I cannot find it at present.

jfheath wrote: ↑Tue Oct 26, 2021 10:21 am

colirv wrote: ↑Tue Oct 26, 2021 8:10 am I prefer to get it right in the first place, using two hands! Zoom in to exactly where I want the via point, minus sign repeatedly with left hand to zoom out to pick up route, plus sign repeatedly to zoom back in, then click to place.

Ah - you are using the XT to enter the route ? In which case I totally agree. The original topic of the post from @jskene was related to using Basecamp - hence my answer related to Basecamp rather than to the XT.

No, I am using Basecamp!

jskene wrote: ↑Tue Oct 26, 2021 11:57 am I never put a waypoint at an intersection, but instead use a point 100 feet down the road, as recommended by jfheath in one of his excellent posts on routing with Basecamp.

Thanks for the mention, and yes that is a point worth using - but I'm surprised you picked up that I recommeded only 100ft down the road. I usually recommend much further than that to stop the satnav taking the turn and then doubling back. I usually say 'some way' down the road !

The problem with doing this is that if there is a shortcut through a housing estate, or along some nail strewn back road, the satnav might take it - but common sense comes into play when you are riding. If you don't take the road it has plotted, it will just plot a new one.

If a single point half way along the road doesn't do the trick, then often two point 1/3 and 2/3 of the way along a stretch of road will sort it out it.

... I usually recommend much further than that to stop the satnav taking the turn and then doubling back. ...

Good point. I'll remember this is the future.

I don't use BC but I put a Via/shaping point (or 2) more toward the half way between the intersections. Zumo will still recalculate based on its settings (fast, short or adv) so I set enough points to force it going my way, unless of course, I do want it to recalculate, say, adv way, so I'll set fewer points.
It sure can happen that I may not zoom-in enough and set a point near the road instead of directly on it. In that case I just follow the magenta line ignoring the point.