Our thinking about urban transport is stuck in the early twentieth century (buses, trams, or light-rail). How about something new? I like the idea of cars and passengers propelled by pressure and vacuum in a pneumatic tube. The propelling “engines” (pumps) and “fuel” (electricity) would not be attached to the moving cars, greatly increasing efficiency. Moreover, in the computer age, there’s no need for an operator in each car, so the payload (the passengers) is most of the weight of the car. The computers can also provide entertainment (although I’m pretty sure they’ll end up being used for advertising).
Bard is the Hackerman-Welch Regents Chair in Chemistry at the University of Texas at Austin, where he has been teaching since 1958.