Is your goal to see some really interesting stuff along the way or just to accomplish a cross country ride? If you want to just ride like hell across the country then take the most direct route. If you have the luxury of time and can take a less direct route then I would give yourself some leeway for points of interest. Actually, I would totally make the route based on points of interst(your interest). If you want to hit as many national forests as possible then you need to plot a course to intercept as many as possible. If you like museums then find them and plot a course. Whatever you are into my friend.....plot a course based on points of interest and not on fastest or most direct route.....but thats me. Good luck and safe travels.