That the president should be able to travel around the country with ease and in safety, with the ability to keep working while in motion, is perfectly reasonable. Sometimes the president just needs to be on the ground in a spot that's not always convenient to get to from Washington, as in the case of a large-scale natural disaster, for example.
And, in the foreseeable future, the president could be able to cross the lower 48 states in about an hour if the Air Force's plans come together.