I ran into this while taking geology courses at university, and the lack of attention to detail by the developers is frankly insulting.
EDIT: The red line is what the developers did. The green line is what they should have done for realism. Explanation in the comments.
Thank you for the explanation! I would however say it's the exact opposite of how a racecar goes around a track, because they try to take the inside of corners rather than the outside.