Weird Routing Behaviour (2)

Having Garmin zumo XT problems? there is loads of help and advice in this forum
User avatar
Peobody
Subscriber
Posts: 1535
Joined: 20 Apr 2021 13:33
Location: North Carolina USA
Has liked: 113 times
Been liked: 335 times
United States of America

Re: Weird Routing Behaviour (2)

Post by Peobody »

rbentnail wrote: 30 Apr 2023 16:52 Coming to a stop sign, in order to go left I have to go right and in about 500 yds make a uturn to go the direction I want to. It's becoming more and more imperative to have prompted recalculation and always either say NO or just ignore it.
Indeed! This is so frustrating. These u-turns are by design, sometimes having a traffic signal that stops oncoming traffic so that u-turners can make the turn. Most are not on the map (at least not yet) which results in an off-route condition. In the example below, if I am heading north on Old Charlotte Rd SW and want to go west on Rte 49 I must turn east and then make a u-turn, (there is a barricade down the center of Rte 49). This is an intersection that is visible on the map and known for no through traffic on Old Charlotte Rd SW so BaseCamp routes accordingly, sort of. The designed u-turn spots are not recognized for what they are. In this case, making the designed u-turn keeps you on the route. Not so when this forced u-turn design is not on the map and the route attempts to take you through the intersection.
Forced u-turn.png
Forced u-turn.png (149.24 KiB) Viewed 1942 times
Routed forced uturn.png
Routed forced uturn.png (266 KiB) Viewed 1942 times
2008 Honda GL1800 Goldwing
1995 Kawasaki ZG1000 Concours
zūmo XT linked to Cardo Packtalk Bold and iPhone SE.
danham
Posts: 307
Joined: 13 Jul 2018 14:25
Location: Cape Cod, MA
Has liked: 99 times
Been liked: 94 times
United States of America

Re: Weird Routing Behaviour (2)

Post by danham »

Apologies if I'm being thick about this, but I don't fully follow your example. I can see that in order to go west on 49 you have to get on 49 east and then do a u-turn. What is unclear (my fault, not yours) is what the problem is for the XT. In your example it obviously worked correctly, but you say that in other cases it would not. If the Old C/49 was one of those cases, does that mean the GPS would tell you to turn left at the intersection of Old C and 49, even though it is not physically possible to do so? If my guess is correct, does that trigger RUT? And why would having u-turns disabled make this all worse?

Thanks for helping me understand (and choose the best settings),

-dan
Zumo XT, 660, nuvi 760 and many retired units dating back to the GPS III+
2018 Kawasaki Ninja H2 SX SE
User avatar
Peobody
Subscriber
Posts: 1535
Joined: 20 Apr 2021 13:33
Location: North Carolina USA
Has liked: 113 times
Been liked: 335 times
United States of America

Re: Weird Routing Behaviour (2)

Post by Peobody »

danham wrote: 30 Apr 2023 19:41 If the Old C/49 was one of those cases, does that mean the GPS would tell you to turn left at the intersection of Old C and 49, even though it is not physically possible to do so? If my guess is correct, does that trigger RUT? And why would having u-turns disabled make this all worse?
Yes, the GPS would tell you to turn left, or go straight if that is your route. The right turn puts you in an off-route situation. If a recalc occurs, you potentially have a messed up rest of the route, likely exacerbated if u-turns are disabled. If you don't allow a recalc and just do a u-turn to get back on the route then all is well. It would not trigger the RUT issue. AFAIK, the RUT issue is only associated with skipping a point.

It is becoming surprisingly common in NC for major roads and state highways to not have any cross intersections for many miles. Instead they have periodic u-turn spots. These are not limited access roads; entrances from side streets and business parking lots are right-turn only. If you want to go left you may have to drive a couple of miles before reaching a u-turn opportunity. I would be interesting to see what a route might look in some of these areas if u-turns were disabled.
2008 Honda GL1800 Goldwing
1995 Kawasaki ZG1000 Concours
zūmo XT linked to Cardo Packtalk Bold and iPhone SE.
danham
Posts: 307
Joined: 13 Jul 2018 14:25
Location: Cape Cod, MA
Has liked: 99 times
Been liked: 94 times
United States of America

Re: Weird Routing Behaviour (2)

Post by danham »

Got it -- thanks very much. The trend in the northeast is to create "jug handle turns" -- you sort of exit right and it loops around left and puts you perpendicular to the original road, often at a light, then you turn left.

-dan
Zumo XT, 660, nuvi 760 and many retired units dating back to the GPS III+
2018 Kawasaki Ninja H2 SX SE
Rofor
Posts: 165
Joined: 19 Jul 2020 08:38
Has liked: 149 times
Been liked: 62 times
Austria

Re: Weird Routing Behaviour (2)

Post by Rofor »

@Peobody
Peobody wrote: 30 Apr 2023 15:20That is definitely not my experience. It calculates a route to the next point AND recalculates the routes between all remaining points. What I am unsure about is whether it handles shaping points added with the BaseCamp Insert tool differently from shaping points created by setting a via point to non-alerting.
My answer was a bit misleading, sorry (couldn't it describe better) - i meant it exactly as you describe it above, and yes - on our findings the Zumo XT uses all shaping points for recalculation, nevertheless how they are created!
Bye, Robert :)
(Actual: Tiger 800 XRx (2016), Garmin zumo XT, Cardo PackTalk, Nolan N70-2GT)
rbentnail
Subscriber
Posts: 932
Joined: 18 Jun 2018 10:14
Location: North Carolina USA
Has liked: 101 times
Been liked: 220 times
United States of America

Re: Weird Routing Behaviour (2)

Post by rbentnail »

danham wrote: 30 Apr 2023 20:41 Got it -- thanks very much. The trend in the northeast is to create "jug handle turns" -- you sort of exit right and it loops around left and puts you perpendicular to the original road, often at a light, then you turn left.

-dan
I grew up in northwest NJ- we had jughandles at least as far back as the mid-'60s. I can still remember the signs- All Turns Keep Right.
Russ B. Zumo 595 & XT
2007 & 2013 USA Yamaha FJR1300A
Fxwheels
Posts: 232
Joined: 13 Oct 2021 13:30
Has liked: 26 times
Been liked: 29 times
United States of America

Re: Weird Routing Behaviour (2)

Post by Fxwheels »

rbentnail wrote: 30 Apr 2023 22:00
danham wrote: 30 Apr 2023 20:41 Got it -- thanks very much. The trend in the northeast is to create "jug handle turns" -- you sort of exit right and it loops around left and puts you perpendicular to the original road, often at a light, then you turn left.

-dan
I grew up in northwest NJ- we had jughandles at least as far back as the mid-'60s. I can still remember the signs- All Turns Keep Right.
Right. They still all there. I'd sure prefer roundabouts like they have many in Europe. It's much safer than a stop signs or a traffic lights. And making a u-turn is easy and fun :)
Plainmad
Posts: 25
Joined: 16 Aug 2020 06:22
Has liked: 4 times
Been liked: 6 times
Great Britain

Re: Weird Routing Behaviour (2)

Post by Plainmad »

This is an interesting article that mentions issues with the XT.
Two identical ones with identical box files but trying to take different routes

https://fliesonthevisor.com/three-days- ... -the-road/
User avatar
Peobody
Subscriber
Posts: 1535
Joined: 20 Apr 2021 13:33
Location: North Carolina USA
Has liked: 113 times
Been liked: 335 times
United States of America

Re: Weird Routing Behaviour (2)

Post by Peobody »

That was an interesting read. Two XT's configured the same, routing differently from the same .gpx file. Yup, they are XT's all right!
2008 Honda GL1800 Goldwing
1995 Kawasaki ZG1000 Concours
zūmo XT linked to Cardo Packtalk Bold and iPhone SE.
jfheath
Posts: 2711
Joined: 19 Oct 2019 16:17
Location: West Yorkshire, Uk
Has liked: 351 times
Been liked: 749 times
Great Britain

Re: Weird Routing Behaviour (2)

Post by jfheath »

I'm not surprised by that behaviour.

Apart from the various ways in which the route may have been altered by Basecamp (by loading into a profile with different preferences, by having different maps, etc); on transfer to the XT (eg different Basecamp Settings, different maps); by the XT on loading or starting off, there are plenty of other factors.

The XTs can load a route and then apply the route preferences stored in the individual XT. They can build up a profile of the rider's style of riding, speeds, type of roads, preferred routes. Unless you can control all of the alternatives, every step of the way, two XTs are very likely to come up with different routes.
Have owned Zumo 550, 660 == Now have Zumo XT2, XT, 595, 590, Headache
Use Basecamp (mainly), MyRouteApp (sometimes), Competent with Tread for XT2, Can use Explore for XT - but it offers nothing that I want !

Links: Zumo 590/5 & BC . . . Zumo XT & BC