To drive or not to drive - That is the question?

We have a 40' DP and are full-timers, both of us drive the motor home. Usually on a trip we take turns driving with 2-3 hours shifts and it makes traveling much more enjoyable. She is an excellent driver and has taken the Lazy Days confidence driver's course. To learn to drive the motor home we hired a truck driver instructor and he gave her a 4 hour lesson which was well worth every cent we paid for the lessons.