I tried the trip planner on my RV760 and it REALLY messed us up. I tried to plot a route to avoid I-95 through downtown Baltimore (can't take propane into the tunnel and the RV760 doesn't know this - even in RV mode). It took us on a really crazy route and we ended up taking about an hour and a half longer getting from Richmond to Aberdeen Proving Ground than it should have taken. Coming back, I used a combination of old-fashioned navigation and the GPS to tell me how far to the next interchange, etc. GPSs are great - but they're no panacea.