For getting an anxious or overstimulated driver from A to B, orienting relative to the direction of travel helps them not-mess-up by misunderstanding their direction of travel or missing their turn. It removes some information they aren't prepared to process anyway.

When the driver has more familiarity and will recognize when an important intersection is coming up, then locking North helps them contextualize the area relative to other major landmarks like highways, lakes, etc.

2) I can read either way, but with a road map what’s in front of you is generally more important than what’s behind you. By selecting the rotating map you don’t just get a rotating map - you get your position pushed to the edge of the screen instead of being centered, which means much more information is visible about the space in front of you. I switched views strictly for this effect.

If only left-handed people were so fortunate