So I’ve managed to work out how to take the route that someone has created on google earth, unzip the KML file out of the KMZ folder, convert it into a GPX file, save it into the correct folder in my phone and open it with OSMand (the off-line GPS program I use).
Now I want to be able to plan and mark out a route on google maps and do the same thing. So I found someone’s step by step instructions online: https://turbofuture.com/internet/How-to-mark-a-route-on-Google-Maps-save-personalised-maps-and-get-backlinks and I made a start, but then when I plotted route that took a “long cut” over a dirt road, once I got somewhere near halfway Google decided it wanted to think for me and plot a shorter route, which had me coming back the other way off the highway. If I backtrack a bit it restores my previous route but as soon as I go a bit further it reinstates the “preferred” route. So if I continue on it will completely remove my “long cut” and have me going via the bitumen. Any ideas brains trust? I’m guessing I might have to add some waypoints somewhere along the way, but I haven’t worked out how to do that yet.