Ah right. Sounds like a setting you might be able to disable?
Might be there, but in light of my experience of using Google Maps it'll take you from now until Doomsday to find how to turn it off. Horrible UI, which seems to change every week to become eversoslightly worse.
I've tried doing that, it then updates the route on the fly to make it fast/faster, which is absolutely what I want it not to do