In the few Mapsource routes that I have done I use waypoints to force the software to take my preferred route. My efforts have been quite amateur but seem to have worked.
With Garmin, at least some units, you can also use waypoints. However some low-end Garmins only have a one waypoint system.
With Garmin, at least some units, you can also use waypoints. However some low-end Garmins only have a one waypoint system.