On many GPS models, including my own crusty Garmin, this requires an additional tap and a longish wait while it renders the map as an illegible squiggle. So I

On many GPS models, including my own crusty Garmin, this requires an additional tap and a longish wait while it renders the map as an illegible squiggle. So I rarely do this unless I want to confirm that I'm going via a specific route, and even then it's only useful if I know the route options beforehand and can tell them apart. As an aside, the Garmin routing is terrible: it (for example) frequently "optimizes" for distance by doing endless zigzags on small roads instead of a single turn on big roads, even when the settings tell it to take the "best" or the "fastest" route. Of course this is to some degree unavoidable when all the brains it has is a tiny on-board CPU; but I've already long since resolved that my next car will have Android Auto, so the cloud can do the work.