Roadways and Paths not recognised
It now appears to me that there is a clear difference between how Garmin navigation works and how the TomTom algorithms operate.
Give a Garmin a Waypoint and it will produce a track between any point on the map and that Waypoint. Where there are no obvious roads or recognised tracks along the route, the Garmin system will draw a straight line, always getting you to the precise Waypoint.
TomTom does no such thing. If you create a location (waypoint) and save it in “My Places” then use this as a destination to create a route, the TomTom system will only recognise proper roads, if your location is not on a recognised roadway, the TomTom terminates the route at the nearest point on the “approved roadways”.
Sounds simple until you want to stop at a Motorway Service stop which is not recognised by the TomTom maps. Just try to create a route from Edinburgh to Glasgow with a stop on the westbound side of the M8 at Hearthill. TomTom simply ignores the stop because it does not recognise that there are services on both sides of the motorway at Hearthill.