I sometimes drive without seeing instruction by motorbike. The instructions and the pricice form of spoken hints should be considered once again. "Turn right" has a very same beginning in the sentence as "turn right in 500meters". I have driven several times 500meters before the right turn to a falce street. Say "in 500metrs turn right" that separates the right turn from warnings!
U-turn should always be a possibility. I noticed that the program generated a new route to my destination automaticly when I did not obey the i structions. A 60km rerouting more than original is to my opinion a way too much. Generating a new route has also some problems, because it is usually meaning that I should make a u-turn instead of continu ing ahead.