Space Efficiency and the Technology of Transportation

If you have trouble thinking about the future, try this idea:

We already live in the future, the one that our parents and grandparents made. They invented things that we take for granted today, but their choices also bequeathed to us some worsening problems, from urban gridlock to accelerating climate change. We are better off because of their inventions, but we might wish they’d thought more carefully about where some of those inventions would lead.

So the most urgent challenge for a 2040 Vision is: Can we be a little smarter than our parents and grandparents were? Can we resist being swept away by the thrill of invention, so that we plan for the consequences of our inventions a little better than they did? When presented with a new technology, can we learn to ask not just “How cool will this be?” but also “what problems arise when everyone is using it?”

To many of our parents and grandparents, for example, the private car seemed like the only tool of freedom that humans would ever need, but like many ideas that sounded great at the time, private cars are liberating only until most people have one, and then they become a problem. The car’s biggest fatal flaw is its very inefficient use of space. That means it’s still a great tool for rural areas and very low density suburbs, where there’s lots of space per person, but an utter failure in dense cities, where there’s simply not room for them all.

There are many other arguments against urban car-dependence, of course, but this one is especially strong because it’s just a fact about physical space: Cars take a lot of space per person. Cities, by definition, don’t have much space per person. Therefore, cars can’t be the main solution to the problem of urban transportation. You don’t need to trust any expert’s advice to understand that. You can’t really argue with it. Your options are acceptance or denial.

If you can recognize a problem as geometric -- such as the need to use space efficiently in cities – you can become a smarter consumer of predictions. Cities will always have relatively little space per person, so no matter what technologies we invent, the amount of space that things take will always matter, and we’ll have to use that space wisely.

You can apply that principle to other inventions. For example, it’s cool to be able to take your bicycle on the train, or put it on a rack on the front of the bus, but only so long as not many people do it. When they do, there simply isn’t room. So we can predict, on geometric grounds, that the large-scale integration of bicycles with transit has to be about providing secure bike parking at stations, not taking everyone’s bicycle on board.

When bike racks on buses were being invented, I was called a killjoy for pointing out that problem. But if we’re going to make smarter visions we need to embrace that kind of geometric skepticism. People who pointed out the geometric problem with cars in cities – that they would be liberating only until most people have one – certainly sounded like killjoys around 1930 or so. But they were right, and in retrospect it’s amazing that anyone could have lost sight of something so obvious.

Even great minds get swept away. In the 1940s, the architect Corbusier unveiled a vision of the future – a “Radiant City” -- in which we would all live in giant towers but still get around on freeways. If Corbusier had done some math, he could have predicted the result: cities that tried his idea quickly ran out of space on the freeways, and had to build massive transit systems to keep their cities functioning.

Will automated cars solve all our problems of space? If used as taxis rather than owned, they will certainly help, especially by freeing up the space that parking consumes today. They will also take somewhat less space per car on the roads.

But automated taxis will still be cars. They will still create congestion when there isn’t room for them all. As cities grow denser but streets don’t get wider, even automated taxis will run out of space.

This is why Southern California will need to keep improving high capacity public transit: rail lines, busways, and frequent urban bus lines protected from traffic as much as possible. When transit is designed to be frequent, reliable, and reasonably fast, it delivers liberty and opportunity to huge numbers of people while taking very little urban space. And because it uses space so efficiently, it should cost less to use. As for automation, by the time we have automated cars we will have all the technology we need to automate trains and buses. Many rail transit lines are fully automated already. The automated city bus may seem fanciful, but it’s an easier problem than the automated car, because buses stay on main streets and move in predictable patterns.

If you want public transit to be supremely efficient, and thus liberating to vast numbers of people, you can’t expect it to go everywhere. It needs straight paths, serving stops surrounded by dense and walkable development, with places for people to access by car or bicycle. But many of Southern California’s boulevards already meet this description, or can evolve in that direction as development fills in and pedestrian infrastructure improves. The opportunities are greatest in the densest areas, but potentially successful transit corridors can be found all over Southern California.

In low-density areas, local buses are an inefficient form of transit, and there is a huge role for shared-ride services, eventually implemented by automated vehicles. But where demand is high, nothing works as well as transit does to move large numbers of people through a city. Again, it’s a matter of space.

What does this mean for the customer? What could life be like in 2040?

Instead of pretending that we know what technologies will thrive in that year, what if we ask ourselves what we want? Perhaps we want ...

  • Ways to travel that can be extremely reliable because they don’t encounter or create congestion, so that for the first time in a century, Southern California becomes a place where you can be sure you’ll get to your meeting on time.
  • An allocation of scarce urban space that respects everyone who uses the city. This can still mean more space for those choosing to pay more, by using a car, but it must also mean room for functional and reliable transit service for those choosing to pay less, and space for everyone whatever mode of transport they use.
  • Enough room in our streets that we can make them great places for everyone, and great places to be, not just to travel.

That’s exactly what great transit systems do. And it’s why, in 2040, transit – big vehicles running fast and reliably in patterns that millions of people find useful and affordable – will be the backbone of urban Southern California.

Author: Jarrett Walker 

Jarrett Walker is an international consultant in public transit network design and policy, with over 20 years of experience in projects across North America, Australia, and New Zealand. He is the president of Jarrett Walker and Associates in North America and also serves as Principal Consultant with MR Cagney Consultants in Australia and New Zealand. He is a well-known innovator in leading the redesign of transit networks, in describing transit issues to the public, in building values-based policies and standards, and in running fun, interactive design processes for transit plans. He has taught graduate level transit courses and now offers a two-day intensive course on transit network design for both professionals and advocates. Walker holds a PhD in theatre arts and humanities from Stanford, and is a passionate advocate of humanities education for careers in supposedly technical fields. He is the author of HUMAN TRANSIT: HOW CLEARER THINKING ABOUT PUBLIC TRANSIT CAN ENRICH OUR COMMUNITIES AND OUR LIVES. In addition to his consulting, teaching, and speaking, he writes about public transit issues at