Or, if you haven't got a garmin (or in my case not copied the maps over correctly) plan a route on Google maps, look at the junctions via street view, and you can open up new routes. did this recently in N Wales - roads I wasn't familiar with, planned a quick hours loop in the hills, checked the route on google, then found out I'd not put the maps on my Garmin. No wrong turns though ! Some good technology out there that helps.