You have to watch a GPS real close when leaving Jerome AZ to Prescott they will route you down 89A if you haven't been that route it is a real treat in a bus with a tow vehicle, hair pin curves with steep grades with 20 mph speed limits with 40 ft restrictions BTDT
...so the feature on the GPS telling me which lane to be in for exits is a huge help, and I have yet to see a paper map with that.