Over the weekend, Steve Waldman tweeted at me:

iphones & public transit: i’ve found smartphones increase the opportunity cost of driving, tilt toward public trans. just me?

Smart, internet connected devices of all sorts have significantly reduced the pain of what were previously dead times — sitting on the train, waiting in the airport terminal, standing in line at the customer service counter, waiting to be called back for your doctor’s appointment (and then waiting for the doctor), and so on. But sitting behind the wheel of a car is not a dead time, however much it might feel like one. You’re constantly assessing road conditions, the behavior of the cars around you, and the behavior of your own car, while you use arms and legs to operate the vehicle. This is why it’s so dangerous to do other stuff while driving; you’re actually very busy.

And so the relative cost of time in transit across modes is almost certainly shifting, as devices become better and faster, and as online activity becomes richer and more flexible. It’s funny; improved technology has been lauded as a way to allow workers to do more from home — to reduce the need to commute. But this is a countervailing effect — reducing the cost of a commute, at least when one isn’t operating the vehicle.

I suspect that better mobile devices will also be a boon for the push to allow autonomous vehicles. People will want them more, and as the temptation of things like the iPad increases, it will become clear that human drivers are obviously a greater danger to each other than are self-navigating cars.