How do I get google maps to stop rerouting my directions?

I am trying to make directions for a motorcycle ride and I want to make my own route by right clicking each turn. But after awhile google changes the route to a main road so it erases everything I've marked. Does anyone know how to make google maps not do this? Or do they know of a website where you can make your own route and get typed directions at the end?|||http://www.google.com/