By Emily Badger, January 17, 2014
The great promise of autonomous cars is not that we could each own one
in our own driveway – the 21st century's version of owning your own
Model T, or your own color TV, or your own bulky Macintosh – but that no
one would need to own one at all.
That's because when cars can drive themselves, they can drive off when
we're done with them. They can pick up other people instead of sitting
parked outside. We'll request them on-demand. They'll pull up out front,
take us right where we want to go, then do the same thing for a hundred
other passengers, a hundred times over. They'll behave, in other words,
like sophisticated ride-share services – or like personalized mass
I've daydreamed about this possibility a number of times with
transportation geeks, and invariably we always wind up in the same, more
sober place: If the autonomous cars of the future will come to look an
awful lot like transit, then what will become of the transit we know
This isn't an entirely silly question in 2014. We make billion-dollar
investments in new transit infrastructure because we expect to use it
for decades. Metropolitan planning organizations are in the very
business of planning 30 and 40 years into the future. The Washington
Area Metropolitan Transit Authority recently released its dream map of subway service in the city for the year 2040. By then, autonomous cars – in some form – will surely be commonplace.
The question of what they'll mean for transit was actually on the program this year at the Transportation Research Board annual meeting
in Washington, where several thousand transportation officials and
researchers met to talk about state-of-the-art asphalts, biker behavior,
and the infrastructure of the future. In one packed session, I heard
Jerome Lutin, a retired longtime New Jersey Transit planner, say
something that sounded almost like blasphemy.
"We’re just wringing our hands, and we’re going to object to this," he
warned the room. "But the transit industry needs to promote shared-use
autonomous cars as a replacement for transit on many bus routes and for
service to persons with disabilities."
Someone in the back of the room did object that many paratransit
passengers need human assistance along the way that an autonomous
vehicle alone couldn't give them. But Lutin's broader point is a
fascinating one: If autonomous cars can one day better perform some of
the functions of transit, shouldn't we let them? Shouldn't we take the
opportunity to focus instead on whatever traditional transit does best
in an autonomous-car world?
"If you can’t get more than 10 people on a bus, or five people on a
bus, then why bother running it?" Lutin asked me after his session.
"You’re wasting diesel fuel."
The implication in this raises (at least) two more questions: Exactly
where (and when) will it make sense for people to use buses or rail
instead of autonomous cars? And if autonomous cars come to supplement
these services, should transit agencies get into the business of
operating them? In my initial daydream – where shared self-driving cars
are whisking us all about – it's unclear exactly who owns and manages
Lutin sounds skeptical that transit agencies will be able to move into
this space. "They don't adapt well to change," he says. They're also
governed by rigid mandates that limit what they can do. A mass transit
agency can't overnight start operating something that looks like a taxi
service. Public agencies also must contend with labor unions, and labor
unions likely won't like the idea of replacing bus routes with
There's also another consideration.
"There's an opportunity for autonomous taxi services to make money,"
Lutin says. "And nobody wants the government to compete with private
industry and make money. We barely tolerate toll road authorities. If it
looks like we can trade in our buses for a fleet of autonomous
vehicles, and we can drop fares and at the same time we can make money,
somebody in the private sector is going to want that."
And if public transit agencies exist in part to subsidize a service the
private sector won't provide, what if that service no longer needs a
"It no longer needs to be a governmental function."
That would leave us then with the more traditional forms that transit
already takes: buses, subways, light rail, street cars. Lutin is certain
that we'll still need transit, particularly in dense cities. An
autonomous car, after all, takes up as much physical space as a car with
a human at the wheel. We'll be able to fit more autonomous cars on a
given roadway, because they'll be smart enough to drive practically
bumper-to-bumper without colliding into each other. But there's still a
finite capacity on the road. And in densely populated areas, buses and
subway cars will still be able to carry more people.
"Theoretically, a highway [lane] can carry 2,200 vehicles per hour,"
Lutin says. "Even if you go to 4,400 or 6,600 vehicles per hour, there’s
still that limit."
So we'll still need transit to get people into the Loop in Chicago, or
across the Bay Bridge into San Francisco, or onto the island of
Manhattan. These are the things that transit already does best, and that
it will still do best in the age of the autonomous car. What's more,
the same technology that will bring us autonomous cars will make
traditional transit better, too. When buses have the same autonomous,
communicating power that cars will have, they'll be able to drive safely
within inches of each other, too. Picture a dedicated Bus Rapid Transit
lane with moving buses queued up end-to-end.
In this world, cars may start to function like transit, but buses could
come to work like trains. And they're a lot cheaper to deploy.