Being forced to go back to a waypoint

[Triplog]

Hi Peobody, I was on a motorway when the recalc took place. It didn't route through the fifth point and stayed on A roads after the motorway until (instead of through a town) then B roads to the destination. I was expecting it to recalc after I skipped the first Viapoint but it didn't until I Skipped the fourth one. I've been using Basecamp (and Mapsource before that) and am familiar with Waypoints and Shaping points but some of the discussions I've seen online made me wonder if Way and Via points were now totally different. Thank you for your "Notes to self" they clarify the needless confusion which was starting to settle in and how inserted points can have different atttributes depending on where they're placed on a map.

[lkraus]

Regarding terminology (Waypoint, Via Point, Shaping Point), notice in your route points list that some are gray and contain "won't alert". Those are Shaping Points. The others are Via Points (alerting). All are referred to as Waypoints.

I think the use of "waypoint" when referring to via and shaping points causes confusion when discussing a Garmin route. I prefer the more specific definitions John Heath laid out in his 590/595 and XT guides. Waypoints are saved coordinates (in Saved/Favourites) which may or may not alert, may or may not even be in a route. If a waypoint is part of a route, then it is either a via point or a shaping point, or a route point if referring to both types of points in a route.

[jfheath]

@Triplog

In your screen shot:

Image1.png (126.16 KiB) Viewed 821 times

The points with orange flags are set as Via Points. Alerting.
The points with blue discs are set as Shaping Points - Not alerting.

This is how they would appear on the Zumo screen.
Ignore the caption at the top which says that there are 6 Via Points. There aren't. This program was developed from a program called Mapsource - it only operated with Via Points, and no-one has corrected the error.

It is not possible to tell for certain from this list whether any of these were Saved as Waypoints.
The dots might be a clue to indicate ad hoc points. A larger dot almost always refers to a known point on the map. The flag might indicate a Saved Waypoint.

So if I was to make a guess, it would be the blue flag which is a saved wyapoint, but I could be wrong. It is impossible to tell for certain. I've tried a number times, but no theory I have come up with works - mainly because you can save the symbol for a Waypoint !

There are two ways to tell in Basecamp:
i) Only waypoints will appear in the lower left pane, along with the route. Other route points do not.
ii) You could inspect the GPX file. Waypoints (ie saved points) will appear with the <Wpt> tag.

@Peobody's description is spot on.

If you want to refer to a refer to a point in a route without specifying what it is, then the term 'route point' not only works, it is also accurate as far as the gpx definition is concerned.

It doesn't matter a great deal - but it can lead to confusion.

For example - I could say - "Waypoints will never have their name changed when transferred to a Zumo XT"
I mean the points created in Basecamp with the flag (waypoint) tool.

Someone else might say - "My waypoint names nearly always get altered by the XT".
But they mean their route point names - thinking that waypoints and route points are the same thing.

Yet someone else will say that you can use waypoints and shaping points in a route.
They are of the opinion that a waypoint and via points are the same thing.

So when we help offer help on these pages we try to use the terminology that Garmin use, which is consistent with the GPX convention.

[Triplog]

Thanks jfheath. Yes I'm very familiar with Alerting and Non Alerting points and how Shaping points can be changed from Non Alerting to Alerting. (I've come from a Mapsource background originally). Thank you for the extra detail though it is very much appreciated!
My initial query was about being forced back to certain route points on the XT2 when my Montana 700 ignores them and happily carries on! I suppose I should stop wondering why Garmin seem to keep changing their programming logic over and over again, I've seen enough of it that I shouldn't be surprised!
But from asking what I thought was a relatively simple question, I have learnt a lot so thank you to everyone who took the time to help me out.

[Peobody]

Hi Peobody, I was on a motorway when the recalc took place. It didn't route through the fifth point and stayed on A roads after the motorway until (instead of through a town) then B roads to the destination.

This fascinates me because the XT2 ignored a shaping point when it recalculated. I am now wondering whether the XT would have. If so, Shaping Points are useless in the planning stage when their purpose is to try to control the route resulting from a recalc.

There has been a lot of terminology descriptive in this discussion which I may now through a wrench into. I has been made clear that a Via Point is an alerting route point and Shaping Point is a non-alerting route point, but, I believe these points are treated differently depending on whether they were created as a Waypoint (Waypoint tool or POI selection), or whether they were created using one of the ad-hoc route point creation tools. In the recalc @Triplog experienced, point 5 was an ad-hoc shaping point, it was ignored. Would it have been ignored if it was a Waypoint that had been changed to a shaping point (switched to non-alerting)? I say no, based solely on my experiences, not on empirical testing. What say you?

[jfheath]

There has been a lot of terminology descriptive in this discussion which I may now through a wrench into. I has been made clear that a Via Point is an alerting route point and Shaping Point is a non-alerting route point, but, I believe these points are treated differently depending on whether they were created as a Waypoint (Waypoint tool or POI selection), or whether they were created using one of the ad-hoc route point creation tools. In the recalc @Triplog experienced, point 5 was an ad-hoc shaping point, it was ignored. Would it have been ignored if it was a Waypoint that had been changed to a shaping point (switched to non-alerting)? I say no, based solely on my experiences, not on empirical testing. What say you?

I don't know. I'll tell you what I do know that may be relevant.

1. Suppose you have a route that takes a particualr road from point A to point Z. It naturally takes the main road route. So you put a point M in it to force it to take you on the nice back roads over the hills and far away.

If point M is one type of point (Via or Shaping), then it route over the hills and far away as intended.
If it is the other type of point (Shaping or Via), then it routes to M, then doubles back to the motorway.

(I cannot remember which was which) I think the former was Shaping point that produced the desired effect. Via Point did the go back. But I could be wrong.



2. When I first got my XT, the first thing I did was to investigate Closest Entry Point. It headed for the the closest Via Point.
Tere was a flurry of software changes after that, and each time the behaviour changed. In turn it headed for :
The closest Via Point
The closest Via Point or any route point that was first created as a Waypoint
The closest Via Point or Shaping point
The closest (ghost) point anywhere on the route.

I don't know if this was very good program development - taking steps to reach the desired goal
Or whether it was programmers not knowing the difference between Waypoints, Via Points, Shaping Points and ghost points.

I'd like to think it was carefully planned that way. But the speed at which the subsequent changes came out suggests not.

[Fxwheels]

Garmin Montana is using the older software not in the XT. It reads the Via or Shaping points differently. I had the 660 and if I missed a point, it would automatically continue on my route. It treated a Via point as a Shaping point, yet it would announce it.
Looks like the programmers who developed that software are left and the new ones rewrote it from scratch...
Montana had different issues, but that's another story.

[jfheath]

The 660 was superb. Plot a route and you could join it anywhere - a fact that was an issue for the easily confused. Circular routes ending at the start point would issue the comment 'Arriving at Destination' and stop the route as soon as you set off. Figure 8 routes also caught people out as at the cross over, if you failed to take the correct road, it would continue to navigate around the wrong loop. But go back and continue along the correct loop, it would continue from there as well.

But the 660 was low on memory and processing power, and the maps outgrew it. I'd still have another though - it had good features which I never really used.

My favourite out of the later models has to be the 590. Ignoring the poor battery connection and dim screen, it is the most reliable and predictable of its successors - the 595 and XT. Thats not just nostalgia, I have all three and use them regularly - just to stay familiar.

[Triplog]

Following on from all that - I don't feel so dense now at my confusion!!! I like the Montana 700 and it's flexibility. Yes it had issues but my main reason for changing was that I was struggling to see the screen detail through the visor and pinlock in certain lighting conditions. The XT2 has solved that issue at least. Heading off for 3 days camping so I'll sit down and digest all this when I get back!

[Fxwheels]

Plot a route and you could join it anywhere

That is/was golden. It beats me why they didn't carry over this function instead of coding the silly "nearest entry point" which does not always work right.
Moreover, there's nothing even like that exists in 396, so to start the route from some random location one needs to be utmost creative.