[bvanevery]

Perhaps it is not so much the case of traveling, but the case of high level context switching. What does "productive" mean to you? If you don't regard public engagements as productive, then I would agree that traveling for them is very unproductive! Otherwise, doing so could be viewed in the same way as a person who runs two types of businesses (e.g. a restaurant and a software shop) in which case switching between those responsibilities takes a lot of start-up time. I'd therefore agree with mburney's comment above that being aware of those constraints should force you to be more efficient.