Interesting point. My impression is telecommuting isn't really much of a factor - not many people, not many days, usually give it up before long. I wouldn't expect the changes in freight delivery to have much impact since trucks are a small fraction of total miles. The lines definitely look a little different in the last decade. However, one can also argue the era after 1991 or so is a long period with no oil shocks, and that might have to do with it. Not saying you're wrong, but hard to tell.

It seems useful to investigate aviation - it's transactions and economic activity, but removes the land use factors that seem like they'd come into play a lot in the highway mileage.