Robocar electronics - CC image from Steve Jurvetson

If we can agree that technology doesn’t change geometry, and therefore driverless cars won’t substantially change the fundamental capacity and spatial requirements of our current auto-based transportation systems, then what would they change?

Chris Bradford takes a stab at this question, taking note of Matt Ygleisas’s prediction of reduced demand for parking. Matt cites the idea of having a driverless car drop you off at a commuter rail station in the morning in order to make use of the higher capacity rail system to enter the city (thanks to the relevant geometries of rapid transit), while the car would then return to your house – eliminating the need for more car storage at the rail station. Chris takes that one step further, noting that with a tireless ‘driver,’ the needs for vehicle storage wouldn’t need to use a set space at all, but could be accomplished through cruising.

While both ideas would reduce the need for parking spaces, they would also increase the VMT for any given trip – either through cruising for parking or for increased deadhead trips, further clogging the streets. This might not be a problem in certain cases where congestion isn’t currently an issue, but it sure wouldn’t help in places where congestion is already a problem.  Bradford notes this:

In fact, this perfectly rational practice will probably be so harmful, so patently selfish, so despised that it will be necessary to outlaw it. Which means everyone will still have to find a spot for his car, driverless or not. Which means that, despite the title of this post, we might not see a robocar apocalypse after all, or a parking bubble, either (other than the existing bubble that local governments have created with underpriced street parking and mandatory parking minimums.)

Perhaps the most interesting application, then, isn’t the need to store a car for personal use (given the issues of storage raised above), but to allow that car to be used productively by someone else.  A driverless taxi, otherwise (hence my choice for my previous post’s image of Total Recall’s Johnny Cab – I don’t know if the new version of the film this summer will depict the Johnny Cab, if it does so at all).

You can already see the convergence of different car ownership models.  A taxi is owned by an operator, they provides rides for hire, charging you for the convenience of the trip in their car and for not having to drive yourself. Compare that to the current point-to-point carsharing model like Car2Go, and the only real difference is the driver.  Both charge based on time and/or distance traveled, both offer point to point trips in a vehicle you don’t own.

While the cost of these robocars would likely come down over time, they’d still be more expensive than regular ol’ human-driven cars, meaning that the trends towards collaborative consumption would continue, and the robocars would serve their best use as taxis.  The value of owning one yourself would be limited, unless you had a ton of disposable income.

As Matt Yglesias put it, “imagine a world of cheap, ubiquitous taxis.”  The net impact would be favorable to cities and those who live in them.  The limits of the automotive geometry and capacity wouldn’t fundamentally change, so this would still be a premium service over much higher capacity mass rapid transportation.  The benefits of owning a car would continue to decline in urban areas, as would the cost of the auto-based alternatives (like taxis).