When navigating, offer a map display mode that shows the current location and the destination. As you move closer to the destination the map would automatically zoom in to show more detail yet keep both current location and destination on the map.
I do this manually. It’s useful for reviewing the live traffic situation and having an intuitive feel for avoiding congestion. Navigation is a good tool but no algorithm beats the human brain for looking at the big picture.
You do get a context-sensitive zoom on the driving console display ... it zooms in for junctions, and zooms out when you are able to drive fast... no point replicating that behaviour on the main screen.