there are certain segments that seem to have bugs. one of my segments is a straight main road and when i try to map my route through it gets to a certain point and then it tells me to back track and take side streets. i even emailed them about it and they were kinda helpful but the bug wasnt fixed. it was nice to get a quick email back from them though. you just have to switch to draw lines until you get passed that "bad" segment and then switch over when its back to normal.