Making changes to a BC route on a Zumo XT

[Mikey]

I recall reading somewhere in the forum; it is risky to modify a Route on a Zumo XT that has been prepared and transferred from Basecamp.

Recently, while preparing for a 180Km ride I wanted to insert a new Waypoint on such a route, in my XT.

This made me wonder, if it is risky as above, is there a ‘list’ of changes that the XT will readily accept and others that will cause navigation problems?

Thank you, Mikey

[rbentnail]

I have never had any difficulty inserting a point into an active route. To me, this is one of the simplest things to do yet so many people seem to have trouble with it. I think it's because I do NOT use the Shape tool. Here's what I do:

With a route active, that is I am following a route on the XT, I touch the map. The screen changes of course. I touch the ARROW top left so the map spins to north pointed to north. I zoom out and scroll to the general area where I want my new point to be, then zoom in as far as needed to properly place my point. I touch the map where I want my point to be. I'm given a list of options so I pick the appropriate one.

That's it. No muss, no fuss, done.

[Peobody]

The "risk" is that when you modify the route, the XT then calculates it. That calculation will likely be different from what Basecamp produced. I am convinced that us mortal can not strategically place route points that shape a route of any significant length in such a way that the XT won't change that route when it does a calculation. This is not a problem for those of us who only want our satnav to get us from point to point, but it is for those of us who want control over the roads we traverse.

[rbentnail]

I used to think that too but my method of single point insertion is very reliable. I do it all the time to get to a petrol station or some eats. The route modifies to include the new point then goes right back to my original route without change. To paraphrase what a wise man once told me, "if your route changes drastically with the addition of 1 point, you don't have enough route-defining points to begin with."

[Mikey]

Thanks to rbentnail and Peobody,
I have just added a flagged route point - Via point, and a blue disc Shaping point directly on the XT map.
I am heading out on my machine shortly (R1250RS) and will see how that all goes.
Cheers, Mikey

[Mikey]

The addition of route points straight onto the XT went well, and I travelled the route with no problems. A beautiful day too!
Thank you for your help.
Mikey

[Peobody]

@Mikey, were you able to tell whether the XT followed the Basecamp route except for the added points?

[Mikey]

@Mikey, were you able to tell whether the XT followed the Basecamp route except for the added points?

Thanks for your interest Peobody, yes the Route was followed faithfully with the XT passing through the newly added route points (added in the XT).

I travel to that particular town a couple of times per month, so I will experiment further with modifying BC routes in the XT.

Mikey.

[jfheath]

When a BC route is sent to the XT it consists of

• A start and an end point
• A number if Via Points
• A number of shaping points
• A large number (hundreds) of invisible gpxx route point extensions - ghost points.

'Ghost points' are plotted at varying intervals along the roads to be followed - typically every few metres.

As soon as you edit a BC route, all of the ghost points are discarded - so you have only the start, end , via and shaping points.

The XT can store separate routing preferences for car and for motorcycle. The Zumo uses the routing preferences that are set in for the vehicle vehicle that is specifies in the route. It also uses the Faster / Shorter option that was specified in the route. If not specified, it uses Motorcycle / Faster.

None of the avoidances that were set in Basecamp are sent to the XT. Instead, the XT uses avoidances that are set in the XT itself.

----

So if you create a route in Basecamp that avoids motorways and ferries, then when you send it to the Zumo, it has the exact route that you sent - held in place with the ghost points.
If you then edit the route, the route is recalculated and the original ghost points are lost. So if the avoidances in the XT are set to allow motorways and ferries, the XT is going to create a very different route.

So when it loses the ghost points - if it recalculates - it is no longer a Basecamp route. Its just a sequence of route points that the XT will use to calculate the best way using the preferences and avoidances that it knows about.

Because the XT and BC uses different terms for road types I find it best not to have any avoidances set, and use shaping points to route away from motorways, ferries and the like in BC, and clear all avoidances in the XT.

It is worth noting that any route that has not been built from scratch on the XT, Is regarded as 'imported'.
In some circumstances if these routes are recalculated, it changes its behaviour and navigates more like a track that has been converted to a trip. Rather than calculating a way to reach the next route point, it calculates a way back to the original route. Often that point will be behind you - and that starts the RUT cycle.

This behaviour doesn't happen with routes that have been created and saved on the Zumo itself. These are 'saved' routes. It is possible to make an imported route be treated as a Saved route.

[Mikey]

Thanks John and friends for helpful comments.

I wrote:
“The addition of route points straight onto the XT went well, and I travelled the route with no problems. A beautiful day too!
Thank you for your help.
Mikey”

However, thinking about the Route I modified on the XT and rode, the route was not a good route for a test. The first 40km is motorway, the next 50km is winding road across a range. There are few/nil parallel or alternative roads (none faster), so I expect the XT, try as it might, was limited in its scope for changing the route. I will try another time.

Mikey.