Start point, how far to avoid RUT?

[danham]

Just curious if anyone has researched how far from your physical starting location the start of a route in the XT has to be to avoid RUT and other issues if the start and your physical location are one and the same.

John's excellent guide says "...a mile or so." But if there is a turn before that mile, is it wise to put the start point after the turn? There have been times I've forgotten to put the start down the road and have done a lap around the motel parking lot to hit the start point, a distance of a few hundred yards, and it worked just fine. But what's the limit? Has anyone done an experiment?

-dan

[Peobody]

I have two waypoints that I use as starting points, one is about 100 yards out my driveway to the right, the other is about 100 yards out my driveway to the left. I have not heard of using these points as a way avoid the RUT problem. They simply give the XT a starting point that is away from where you physically are. I have had routes where the starting point was the hotel I stayed in the night before. I started to drive across the parking lot and before I got to the street the XT ended the route with "you have arrived". Now my starting point for every route is somewhere slightly down route of the physical location where I'll depart from.

Oh, I also remember a loop route I created where home was both the start and the end point. The XT said I had arrived before I got out of my driveway. At least one Via point in the route would have prevented that but I did it early in my days with the XT and Basecamp. When I was trying to absorb advice and listened to folks folks who said that you only need Shaping points. I didn't understand to conditions associated with that statement at the time.

[rbentnail]

I've had starting points as far as 5 miles down-route from my actual location. This allows me to ride somewhere for breakfast, somewhere else for fuel, etc. then start the route and route to my start point. I rarely start any route from anywhere near my house- a mile or two down-route seems to work fine.

[lkraus]

I think the question could be re-phrased as "How near a via point to I need to be to `pass through' it?" I think the answer to that is probably around 30-50 feet (10-15 meters). I've not tried to actually measure that distance, but am basing my guess on how far off route I've been when the "Recalculate?" question has arisen.

Put your start point someplace you know you will NOT be when you begin riding. My routes from home all start at one of two saved waypoints, each about 500 ft North or South of my driveway. Travelling, and starting the day's ride from a location that may not be known exactly, I like John's recommendation to pick a point on the way out of town, which provides a lot of flexibility. I don't usually care about the route for the first mile, let the Zumo figure that out.

[jfheath]

As long as your start point is ahead of you and you actually pass through it - after your satnav has got a good satellite fix - ie is ready to navigate - then you are good to go.

The danger is sharing a route with a load of mates. Half of them will be on the wrong side of the start, or will not wait for the ready to navigate message before they set off and pass the start without the satnav recognising it.

With the XT and 590/595, I was quite happy for that point to be beyond the ring road when leaving a town. It worked well when searching for fuel before setting off.

With the XT2, I am not so sure. It does something different when starting a route that made me think that having the start a long way away may not be a good idea. Something I have yet to work out. But that's the XT2 so not an issue for this discussion. As close as you want in front of you, or as far ahead as you want.

[rbentnail]

As close as you want in front of you, or as far ahead as you want.

In my experience, not exactly. I have to be cautious how I get to my start point otherwise the "cannot calculate route" kicks in. I have had to stop then restart the route, sometimes more than once, in order for the XT to choose a route on the road I'm currently on. It will often want to take me 4 or 5 miles out of my way instead of 1.5 miles straight ahead.

[jfheath]

I didn't answer @danham's question fully. Missing the start point doesn't cause the RUT issue. Yes you get repeated u turn requests but that is because it is trying to get you to go back to visit the point that you have missed. Not because it is trying to get you to go back to the last point it asked you to u turn.

But one of the ways of escaping that is to use skip. And that can trigger RUT behaviour when you next deviate.

@rbentnail - I've yet to have that behaviour, but clearly it is an issue. I'll have to check that out.

[jfheath]

I think the question could be re-phrased as "How near a via point to I need to be to `pass through' it?"

Now you phrase it like that, I think that I know the answer.

My casual observations are that as soon as you hear the announcement...eg "Approaching orange flag in .7 miles on the left, then it assumes you have visited it. I spotted this when I put a via point just after a left hand turn junction. That is the Via point was about half a mile ahead on the road that I was traveling. It announced. I realised it was misplaced and turned left before reaching it. It didn't care. I checked the Skip button. It was not showing as the next point to skip. The one after was.

There is the opposite situation to that. You put a via point just after a junction on the road you wish to turn down. Quite possibly by accident. That point will not announce until it has finished announcing the turn left command. Which means that a point positioned like this will never be recognised as being visited.

These are casual observations which I checked out a couple of times. But it isn't thorough research. If you have info that indicates this isn't correct, plaese yell out.

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Zumo XT. If you have skipped a point previously, the route changes its nature. if it is navigating - say straight across a roundabout to take you to a via or shaping point in (say) a village -e g for coffee. You ignore it - decide not to stop, so take the third exit, by-passing the village. The XT spots the route emerging onto the bypass a couple of miles ahead AND IT DELETES THE VIA/SHAPING POINT so you don't have to visit it. I have a couple of videos of it doing this that I'll dig out when I get back.

[OldRS]

I do not know what "RUT" stands for but, as afar as I am concerned, the most significant failing in all of Garmin's products after the 550 was the removal of the the option to be guided to the start of a route or for the device to monitor ones progress and start guidance when the route was crossed.

[danham]

It's either "Repeated U Turns" or just a pun referring to the XT getting stuck in a rut involving repeated U-Turns. Either way:

app.php/ZXT-P103

-dan