How do you plan for the unpredictable? That’s the question facing the more than 400 metropolitan planning organizations (MPOs) that have been tasked by Congress to write 20-year transportation plans for their regions. Self-driving cars will be on the market in the next 10 years, are likely to become a dominant form of travel in 20 years, and most people think they will have huge but often unknowable transformative effects on our cities and urban areas. Yet not a single regional transportation plan has tried to account for, and few have even mentioned the possibility of, self-driving cars.
Instead, many of those plans propose obsolete technologies such as streetcars, light rail, and subways. Those technologies made sense when they were invented a hundred or so years ago, but today they are just a waste of money. One reason why planners look to the past for solutions is that they can’t accurately foresee the future. So they pretend that, by building ancient modes of transportation, they will have the same effects on cities that they had when they were first introduced.
If the future is unpredictable, self-driving cars make it doubly or quadruply so. Consider these unknowns:
- How long will it take before self-driving cars dominate the roads?
- Will people who own self-driving cars change their residential locations because they won’t mind traveling twice as far to work?
- Will employers move so they can take advantage of self-driving trucks and increased employee mobility?
- Will car-sharing reduce the demand for parking?
- Will carpooling reduce the amount of vehicle miles traveled (VMT), or will the increased number of people who can “drive” self-driving cars increase VMT?
- Will people use their cars as “robotic assistants,” going out with zero occupants to pick up groceries, drop off laundry, or do other tasks that don’t require much supervision?
- Will self-driving cars reduce the need for more roads because they increase road capacities, or will the increase in driving offset this benefit?
- Will self-driving cars provide the mythical “first and last miles” needed by transit riders, or will they completely replace urban transit?