Our personal experience has taught us to always double check- always. We check the GPS route, verify on the map that it is what we truly want to do and if it is- go. But I'll bet that about 50% of the time we will have issues with part of the route and will modify it. This is particularly true in rural areas where the mapping can be a little sketchy. It has often tried to send us down roads that don't exist in real life- but apparently are platted on a map somewhere. Even our own home address- the GPS is about a mile off. Like Ronald Reagen told the Russians- trust... but verify.