For others looking in, I should explain that Rami (mdxix) and I are exploring some undocumented behavior of certain Garmin software and certain Garmin GPSRs. We do not know how widely this applies, and of course Garmin could change it at any time.
The first part, roughly half, of a GPX file created by MapSource v16 contains a collection of wpt
elements called waypoints. The second half contains the routes as rte
elements. Each route includes an ordered sequence of rtept
elements, which repeat the information in the wpt
elements. We call these route points; MapSource names them Map Points on its display.
MapSource does not permit moving or editing Map Points, although one can delete them.
Now, on to what we have found.
To clarify, the sample Green Mountains GPX file I provided was not calculated or created by a computer.
Sure it was, probably by my copy of MapSource, or another volunteer's, maybe by Jennifer's at ACA.
Fred & Bill, can you try loading the Green Mountains file on your GPS? It is at
I have stripped this file from any waypoints. Can your GPS navigate its routes? Does it show you that it did not add any waypoints?
... As far as I can tell, when you choose a route to navigate, you are choosing it from the second part of the file, not the first. I know this because I can completely delete the entire first part of the file and still navigate just as well. Only the GPS memory is not exhausted by waypoints. See the screen images I posted earlier.
Does the same happen to you with the sample Green Mountains file?
My old GPS-III+ ignores the route points entirely, showing no waypoints and no routes.
My GPSMAP 60CS seems to work like your unit, showing the routes and the route points, but no waypoints. It does navigate the route, in both off-road and follow-the-road modes. No editing, though, except to delete route points, just as in MapSource.
I took it one step further to see what the 60CS does to a route when a waypoint on it is present and is moved by editing in the GPSR but the route is not edited. When asked to navigate the route, the unit follows the change. I'd summarize it by saying that the 60CS uses waypoints info when present, otherwise uses the route points.
The Green Mountains Loop is small enough to fit in Bill's 60CSx without any of these manipulations. I just tried the same procedure on the Northern Tier, which is his concern. Indeed, the waypoint limit of 1,000 is not a problem because there are no waypoints. However, the route limit of 50 in my 60CS was reached. Bill, do you know the route limit on your receiver? If it's 100, and if your receiver will navigate from the route points like Rami's and mine, you could do this in one load. You would give up the ability to edit the route on the road.
My own choice would be to keep the waypoints anyway, maintaining the ability to edit, as reloading once or twice on a 3-month ride is not that large a hurdle. But it could be for you.