Avoid the issue by using the same maps to plan the route as you will be using on the device when you ride it.
That usually means using mapsource / basecamp at some point in the process.
You're missing the point here - I want to use the OS on Memory Map to plot my routes as, in my view, it's the best mapping in the whole world!
From bitter experience many of the other mapping systems have roads that don't exist and others that do exist not appearing .... Mr Google has a classic near here where a RIVER is clearly displayed as a ROAD!
As I said in the OP the issue isn't mission critical, just a bit annoying - but I'd like to know the answer as to why.
Rob
The answer as to Why is simply that the maps are different.
You plan a route on one map, and you get a bunch of points which you ask the device to navigate between.
On the device, it then depends whether you are following a Track ( simply a highlighted trace overlaid on the map );
or a Route ( active on-road navigation with turn-by-turn directions ).
If you are following a Track, then it really doesn't matter if the planned track doesn't exactly follow the road, you can see what it means.
Following a Route is a different matter.
If the list of routepoints does not fall on the roads of the routable map in the device, it will not work properly.
Or if some of the roads that you used in planning the route do not exist on the device's maps.
If you want to use Routes, then I'd advise you to follow this workflow:
- Plan your route on the website of your choice.
- Export is as a GPX Track.
- Bring this into Mapsource / Basecamp which has the same maps as your GPS device.
- Create Routes in Mapsource / Basecamp which follow the Track, but using the Garmin mapping you will be using.
- Constrain the Routes as required to follow the planned Track.
Send both the Track and Routes to the device.
Set the Track to Always Display.
Navigate the Route.
