I think I understand the whole rhumb line and great circle idea but I can't seem to find an answer on this question. Suppose I am driving a car (i don't use ship because I don't want to put the constant compass bearing idea on the table) and that I can move for quite a long distance on land (across Russia for example) without any obstacles. If I keep the steer fixed so that the car moves dead ahead will I be following a rhumb line, a great circle or none of these. I've found this on wikipedia: > If you were to drive a car along a great circle you would hold the steering wheel fixed, but to follow a rhumb line you would have to turn the wheel, turning it more sharply as the poles are approached but everything else I've found seems to contradict this. And yet I'm not sure if keeping the steer fixed means fixed dead ahead or fixed turned at 30 degrees left for example.