Photo by jurvetson on Flickr.

Driverless cars will bring many changes to the way we see transportation. Some will be very good, some bad. But some commentators aren’t convinced when I say a huge fight is brewing over how much the road system defers to pedestrians and cyclists or pushes them aside.

In Mother Jones, Kevin Drum wrote:

[E]ventually you won’t even be allowed to drive a car. Every car on the road will be automated, and our grandchildren will be gobsmacked to learn that anything as unreliable as a human being was ever allowed to pilot a two-ton metal box traveling 60 miles an hour.

When that happens, it will be a golden age for pedestrians. Sure, cars won’t need signals at intersections, but neither will people.

If you want to cross a road, you’ll just cross. The cars will slow down and avoid you. You could cross blindfolded and be perfectly safe. You’ll be able to cross freeways. You’ll be able to walk diagonally across intersections. You’ll be able to do anything you want, and the cars will be responsible for avoiding you. Your biggest danger will come from cyclists and other pedestrians, not cars.

It would be fantastic if this scenario came to pass, but is it realistic? It’s certainly possible computers can get smart enough to handle it, but the sticking point here is the words “will slow down.”

How much will they slow down? For how many pedestrians? Drum lives in Irvine, California, which has few pedestrians, so perhaps the cars can just avoid the occasional pedestrian. But in urban areas, there are a lot of pedestrians. If everyone crossed whenever they liked, the cars would slow down an awful lot.

In some places, cars would hardly ever get through. In almost any major city’s downtown during a busy period, pedestrians are waiting in large numbers on street corners to cross. The only reason cars can get through is because signals govern pedestrian crossings. And when a light is green, often a car has to wait for a gap in the pedestrians or gently nose through to get past.

In Kevin Drum’s future urban cores, constantly crossing pedestrians mean that car traffic will not flow at all except perhaps in the wee hours. Anyone who’s been involved in a proposal to take away a lane of a road for bikes, or for a road diet, knows that drivers (or, in the future, car riders) will not stand for it.

Drivers are a powerful political force

Just look at, for example, the backlash against a bicycle lane on Prospect Park West in Brooklyn. In a very liberal jurisdiction, a modest and overwhelmingly successful bike lane nevertheless stirred up a few wealthy and well-connected individuals, including the wife of Senator Chuck Schumer (D-NY), to create an organization and file lawsuits to block the project using any means necessary.

Tea Partiers certain that there is a vast UN conspiracy to force them to live in high rises are opposing even extremely modest state laws creating some incentives for development in dense areas. Do we really think people will let government mandate that nobody is allowed to drive a car by hand, and that pedestrians get absolute priority?

In the DC area, some bicyclists ride on MacArthur Boulevard in Potomac, a narrow and windy road in a low-density area. That’s perfectly legal, but there’s a constant stream of letters to local press outlets by drivers who are sure it must be illegal to bike there since it slows them down.

Forcing drivers to travel slower would be like telling seniors that we’re cutting their Medicare. The political counter-pressure is intense, so much that most transportation planners always take great pains to reassure drivers of how any change won’t really slow them down. Even for the pedestrian plaza in Times Square, one of the early promises from the mayor’s office was that it would actually reduce car delays.

I can go on. But anyone who writes regularly about transportation has encountered the massive sense of entitlement from drivers. When I’m driving, I hate to be delayed, too, but I squelch this natural impulse because I write about the issues and have context.

It may well come to pass that driverless cars have to travel slower and pedestrians are able to act more freely. But this will create tremendous political pressure to change the social compact over roads to get traffic moving faster once again. And in this, we will see another, more intense variant of the same fight we have today.

Once, pedestrians did walk freely, and children played in the streets. As automobile use proliferated, rising deaths led to campaigns to segregate street space. Our society could have taken one of two approaches: it could have limited drivers, and added legal liability to force drivers to be more careful, or it could get people out of the street. Many places in Europe chose some elements of the former, but America decisively chose the latter: to redefine the street’s role in society to move cars faster. I’m certain that in Drum’s scenario, there would be intense pressure to do the same.

Who is liable?

One element determining whether driverless cars turn into the Kevin Drum reality or another one is how we treat liability. When a driverless car kills a person, whether due to a human overriding the technology or a failure in the computer system, there will be a lawsuit.

If courts hold that the manufacturer of the car is liable, this will stifle development of the cars. The technology might ultimately be perfect, but it won’t be perfect from the start. Manufacturers will ask state legislatures to limit their liability. Already, a number of commentators have called for liability caps or other legal changes which shift the burden away from the manufacturer.

If the legislatures don’t agree, then manufacturers will have to move very carefully until they can make the cars virtually incapable of killing anyone. That will likely hinder development in general, and make any self-driving cars travel slower than human-operated cars. Many drivers therefore will turn off computer mode a fair amount of the time, and political pressure will build to change the liability standard. This will be an early skirmish in the battle over the cars’ speed.

If states do limit liability, then we’ll end up with a different situation. Buyers will want driverless cars that use algorithms like the one the University of Texas team devised that let them move faster. Sometimes those cars will travel close to pedestrians or bicyclists. Most of the time they’ll still avoid killing anyone, but mishaps will happen. And like in today’s legal world, prosecutors, judges and juries will be very reluctant to impose heavy punishments on someone operating a car who unintentionally kills another.

Then we’ll be back to a situation like the early 1900s roads. For people’s own safety, officials will start imposing restrictions on pedestrians. It’ll start in places like Irvine. If laws won’t stop people from walking on highways or crossing diagonally, then they’ll build fences, or skybridges, or both.

Today, one argument against restricting pedestrians too much is that not everyone can drive. Seniors and people with disabilities can’t operate a car, and many can’t afford them. When driverless cars become commonplace, there will also be cheap taxi service, and so it’ll be easier just to tell people to call up a car.

Already, many suburban areas are essentially an archipelago of human-accessible islands in a sea of almost-cars-only space. Little will stand in the way of making this other space absolutely cars-only. And why not? After all, without people, cars can use fancy algorithms to interweave with each other and zoom around far faster than they could in 2012.

Driverless cars aren’t bad

A number of the responses seem to be reacting to an imaginary variant of my thesis, in which I said that self-driving cars were going to be a unmitigated bad thing. There’s a natural tendency to simplify all arguments into “x is great!” or “x is terrible!”

The fact is that autonomous cars are coming whether we like it or not, and like any technological advance, will bring both terrific improvements to people’s lives as well as drawbacks.

Driverless cars are sure to lead to big fights. Will they shift the balance farther toward pedestrians, as Kevin Drum believes, or away? I hope the former, but the technology won’t magically solve this problem. Instead, we’ll have to fight it out through the democratic process, as we do most other issues affecting the public sphere.

David Alpert is Founder and President of Greater Greater Washington and Executive Director of DC Surface Transit. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He lives with his wife and two children in Dupont Circle. Unless otherwise noted, opinions in his GGWash posts are his and not the official views of GGWash or DCST.