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Complex Riding Routes Doubling back
Posted: Thu Jul 02, 2020 2:28 pm
by JohnnyRidesAlone
I have ridden with Zumo’s for a good while now. 550 – 660 -590 and now XT.
I shall try to explain my issue. I go away each year to an area. Strictly speaking I am not touring but riding the area. So I build highly complicated routes seeking out every twisty. A typical day is 200 miles but I don’t move any further than 40 miles from my hotel.
But one thing that impedes me is that from my 550 days I never build a route where I go back on myself. I write on continuous route which never touches another part of the route. This is because it really used to mess up the 550 and ruin the entire route. Does the latter 590 and XT have that issue or is it sorted now?
See attached examples first OK second avoid
- OK .JPG (116.37 KiB) Viewed 2290 times
- Never.JPG (68.92 KiB) Viewed 2290 times
Re: Complex Riding Routes Doubling back
Posted: Thu Jul 02, 2020 2:46 pm
by sussamb
If you place enough via and shaping points it shouldn't be an issue. The current trip planner on all modern Garmins wont allow you to bypass a via point unless you take action to do so, so I'd place viapoints a few hundred metres past any point where you cross over or intersect with another part of the route.
Re: Complex Riding Routes Doubling back
Posted: Thu Jul 02, 2020 8:56 pm
by Joby
You can check your routes before you go by sending them to the device then choosing Settings --> Navigation --> GPS Simulator. Then execute the route and leave it running while you watch something on TV. If the simulation makes it right round the route it should work fine in the real world.
I've not experience any problems with overlapping thus far. If you have only plotted non alerting via points (known as shaping points) the unit discards ones you've missed if you stay on the route. So I suppose the scenario could arise where it thinks you've passed one on the return leg and discards the rest. I've not tested that in the real world yet to see what happens.
If you PM me and send me the route I can take a look at it.
Re: Complex Riding Routes Doubling back
Posted: Fri Jul 03, 2020 1:54 am
by Iris
I have the 590 and I do routes like the complicated one (the 2nd one you show). I do them all the time.
It works well. Sometimes while I’m riding I have to zoom out a bit to see the white arrow showing which way to go.
Sent from my iPhone using Tapatalk
Re: Complex Riding Routes Doubling back
Posted: Fri Jul 03, 2020 2:00 pm
by JohnnyRidesAlone
OK Thanks to all. What would happen is that you would start a route and have 250 kicks and a finish time of 14.00 say. If you hit the crossing points it could go crazy and end up with a vastly reduced or increased end time
Re: Complex Riding Routes Doubling back
Posted: Fri Jul 03, 2020 6:10 pm
by jfheath
The 590, 595, 39x and XT are all much better behaved at cross over points in a route - providing that you plot the appropriate type of route points.
The problem that you are describing was something that happened with the 550 a lot. Although it would follow a route precisely, at the cross over point or where two routes touch it was all too easy to go wrong - if you didn't happen to notice the crossover looming on the map as you approched. And circular routes - well it would finish the route before you even started.
The 660 made improvements to this. A figure of 8 route was very interesting at the crossover point. Take one branch and it would happily navigate from that point in the direction that you were traveling. Realise that you had taken the wrong branch, and go back. About 50 metres from the intersection, the satnav would continue navigating that leg correctly. As long as you were on one leg of the route after the cross-over, it didn't care if you missed out an entire loop. Don't get that statement wrong - it would navigate you in the correct direction, but if you strayed onto the wrong section of the route, it would assume that you did it on purpose, rather than being stupid (which is generous of it - we all make mistakes).
But it raised a lot of complaints from people who ride long routes and somehow managed to take the wrong route.
So the 590 came along, and with it a whole new set of definitions and requirements for plotting a route. These are the devices with the Trip Planner App - the 590, 595, 39x and now the XT. And they use of two kinds of route points - shaping points and Via Points. I might have remembered incorrectly, but my belief is these names were used before, but they now have different purposes.
Create a route on any of these devices with just shaping points, and it will navigate just like the 660 used to. Except that shaping points are silent. Unless you spot the little blue circles on the satnav screen, you don't know that you are approaching them. But deviate from the route and join it in a different place and it will navigate you from where you are to the next shaping point along the route. It doesn't matter how many shaping points you have missed, it will take you to the next one from where you are now. You can do the same trick with the figure of 8 as you could with the 660.
To illustrate this with a route with 10 shaping points numbered 0 through to 9. If you rode 0, 1, 2 and then went off route and picked it up just before 7, it would take you then to 8 and 9. All the while it knows that 3 is the next point in the sequence and will continue to find ways to get you to go back to it, but as soon as you get onto the route approaching point 7, it no longer cares about 3,4,5, and 6. You are on the route and you have missed out only shaping points. It will keep nagging you to go back to the first missed point but as soon as you get on the original route to point 7, it stops the nagging.
But now we have Via Points which are really heavy duty points which hold the route firmly in place. The satnav insists that you visit a Via Point. So if you put a Via Point 'V' into the example above so that you have a route 0 1 2 3 4 V 5 6 7 8 9 and you try the same trick as described above taking a different rout ebetween 2 and 7 , the stanav is having none of it.
Point 7 occurs after the Via Point V so even though you are on the correct route having missed 3 4 V 5 6, you have not yet visited V and it will continue to take you back to the first point that you missed. Point 3.
It will however let you go off route after point 5 when you eventually pick up the original route between 8 and 9 . It will then continue to navigate to route 9 - once more not caring that you have missed out 6 7 and 8. (But it will continue to try to navigate you to the first point you missed. Point 6.
To answer your question more succinctly. If you use Via Points sparingly and carefully, the 590 and later satnavs will never get confused at a cross over point. Put a Via Point in each section of the route after the cross over. It will treat each section between Via Points as a separate stage and navigate that. (Start and Finish points are also Via Points).
To finish the story - having decided that Via Points were needed to force the route for users that couldn't navigate the cross over of a figure of 8, they then discovered that it was necessary to allow users to skip a Via Point if necessary. So that feature was added in one of the software upgrades. The Skip Button.
SInce then a couple more features have been added. The 595 introduced an auto-skip feature. Ignore the instructions to get you to go back twice, and it asks if you want to remove the point from the route. Which is nice - or it would have been if they had thought about it a bit more carefully.
In the XT, they did - and displayed the name of the point to skip - which is a big help. They also added an option to start navigating the route from where you are now.
Re: Complex Riding Routes Doubling back
Posted: Fri Jul 03, 2020 7:12 pm
by sussamb
Very comprehensive reply which I'm sure will help many here. You must be able to type though, would take me half a day to write that lot out
Re: Complex Riding Routes Doubling back
Posted: Sat Jul 04, 2020 1:33 pm
by JohnnyRidesAlone
A big thanks to JF for the comprehensive post which made a lot of sense. I guess i was like a car driver before ABS "never use your brakes in a corner"
The 550 did have a lot of issues and in many ways was inferior to the old LCD version it replaced (as my then riding pall told me a lot.)
I am going to push the boat out and intro some cross overs because that way I can squeeze the most out of my tours. If I read correct maybe I should place some "alert on arrive" just after the crossing points?
This really is a valuable as without this multipoint guidance you may as well use your phone.
Thanks again for taking the time and explaining it very carefully
Re: Complex Riding Routes Doubling back
Posted: Sat Jul 04, 2020 3:21 pm
by jfheath
JohnnyRidesAlone wrote: ↑Sat Jul 04, 2020 1:33 pm
I am going to push the boat out and intro some cross overs because that way I can squeeze the most out of my tours. If I read correct maybe I should place some "alert on arrive" just after the crossing points?
That's is absolutely correct. But think a mile or two after the crossinng point rather than 'just' after.
-----
That is too short an answer for me. Sorry. Here is the detailed bit:
You can imagine thatThe Via (Alerting) Points break the route up into sections. In effect it picks up one section and navigates it start to end. You must visit the Via Point at the end of a section. So it doesn't know about the rest of the route or the part where two sections of the figure of 8 share the same road. So there is no way that the satnav will consider jumping into a different section - unless you are over-enthusiastic with the skip button.
I don't think for a moment that this is what it actualy does, but it is a good picture to have in your head by way of explanation.
But I wouldn't put the Via Points
JUST after the crossover. I have noticed a couple of times that once it has started to announce arrival, it is treated it as having been visited. And that can be half a mile before actually reaching the point.
Think of an actual figure
8 - also one which has a longish shared section in the middle
Anywhere in the top circle and anywhere in the bottom circle. But to be consistent with other advice I give, I would be tempted to put it on the first section of clear road away from the intersection.
Exampe: I put my start point a couple of miles away from where I know I will be starting. If I am in a town, my start on my road away from the town but after any ring road. That could be 5 miles away. I also use them
after a potential coffee stop. Put one on the road I want to be on after I have wandered around a town. That point will be on the same road that I would take if I don't wish to stop. It gets me to where I want to be.
I'd give the same advice in the cross over situation. Put the Via Point on the road you want to be on well after the crossover has been cleared. It gives the stanavv the opportunity to get you to the right place even if you have a detour or if the cross-over area contains some irresistable attractions.
Thanks for the comments by the way ! Much appreciated.
One more thing - [mention]Joby[/mention] 's suggestion of simulating the route. Its handy to see what the route is doing, but it follows the route precisely, and wouldn not identify this particular problem.
The problem arises when the magenta line for one section of the route shares the same bit of road as the magenta line for the other section. If you are on this section for the first time you need to take the left branch (say). If you take he right branch, or you wander off to the other side of the road - perhaps to overtake a car, or the building around are interfereing with the satellite fix - the satnav may well think you are heading for the right hand branch and navigate you accordingly. This is theoretically possible if you use just shaping points.
That Via Point locks the route into place. You have to visit that point next.
Re: Complex Riding Routes Doubling back
Posted: Sun Jul 05, 2020 4:04 pm
by JohnnyRidesAlone
Thanks again. interesting that you mention start point. We always have these a good way from the hotel. My old riding bud used to put them bang on the hotel and could never understand why we did not. Sometime you would have to go the wrong way to pick up the start point. In anycase I shall now give this a go and again say thanks for your help