How roads could beat rail

By Felix Salmon
January 24, 2013

The best conference panels, like the best blog posts, are the ones which change your mind. And while I haven’t done a U-turn on anything, after yesterday’s panel on smart cars I’m now thinking very differently about the relative merits of various ways of improving how we move around where we live and travel. While I’ve generally been a fan of just about any alternative to the automobile, now I’m not so sure: I think that smart car technology is improving impressively, to the point at which it could be the most promising solution, especially in developed parts of the world like California.

One reason is simply fiscal. Projects like the self-driving car, and the Sartre platooning project in Europe, move the costs of new technology onto companies (Google) and individuals (people buying smart cars). As such, while the total amount of money spent might well be enormous, the money doesn’t need to be spent up-front by any state or national government. That stands in stark contrast, of course, to rail projects, which cost billions of dollars up front; if they ever do pay for themselves, they do so only very slowly.

It makes perfect sense for dense urban areas to invest in subway systems, of course — as China is doing; India should follow suit. A pedestrian-friendly city with a great bike-path network and a fast subway system is basically any urbanist’s dream, both energy-efficient and reasonably low-tech. But between cities and suburbs, or between cities, you need other ways of getting around. And here there are real choices to be made, between rail and roads. Or rather, given that roads are necessary, do you build roads and railways, or can you solve all your problems with roads alone?

China of course is happily blasting new railways through the country as part of its massive national-infrastructure project. But the more developed a country becomes, the more expensive and time-consuming any new rail line will be. And if you’re looking out say 20 years, there’s a pretty strong case to be made that the kind of efficiency that we can get today only on rail lines will in future be available on roads as well — with significantly greater comfort and convenience for passengers.

Right now, technology is arguably making roads and cars more dangerous. Drivers are notoriously bad judges of their own driving ability, and they’re increasingly being distracted by devices — not just text messages, any more, but fully-fledged emails, social-media alerts, and even videos. What’s more, when car manufacturers roll out things like stay-in-lane technology, that just makes drivers feel even safer, so they feel as though they have some kind of permission to spend even more time on their phones, and less time paying attention to the highway. The results can be disastrous.

But once we make it all the way into a platoon, or in a self-driving car, then at that point we become significantly safer than even the safest human driver. While we’re very bad judges of our own driving ability, we’re actually incredibly good at intuiting how safe our driver is when we’re a passenger. And the experience of people in self-driving cars is that after no more than about 10 minutes, they relax, feel very safe, and are very happy letting the car take them where they want to go. They even relax so much, I’m told, that they lose the desire to speed — maybe because they know that they’re getting where they’re going, and in the meantime can lose themselves in their phones.

If and when self-driving cars really start taking off, it’s easy to see where the road leads. Firstly, they probably won’t be operated on the owner-occupier model that we use for cars today, where we have to leave our cars parked for 97% of their lives just so that we know they’re going to be available for us when we need them. Given driverless cars’ ability to come pick you up whenever you need one, it makes much more sense to just join a network of such things, giving you the same ability to drive your car when you’re at home, or in a far-flung city, or whenever you might normally take a taxi. And the consequence of that is much less need for parking (right now there are more than three parking spots for every car), and therefore the freeing up of lots of space currently given over to parking spots.

What’s more, the capacity of all that freed-up space will be much greater than the capacity of our current roads. Put enough platoons and self-driving cars onto the road, and it’s entirely conceivable that the number of vehicle-miles driven per hour, on any given stretch of road, could double from its current level, even without any increase in the speed limit. Then, take account of the fact that vehicle mileage will continue to improve. The result is that with existing dumb roads, we could wind up moving more people more miles for less total energy expenditure in cars — even when most of those cars continue to have just one person in them — than by forcing those people to cluster together and take huge, heavy trains instead.

This vision creates a dilemma, when we start facing choices about building rail lines or new suburbs. We’re not in a self-driving-car utopia yet, and the transportation problems we have are both real and solvable using rail. So do we use the tools we have, or do we wait and hope that future technology will solve our problems in a more efficient way?

And the question of building infrastructure applies to cars, too: do we just allow the auto industry to build ever more efficient gas-powered vehicles, which will eventually become self-driving, or do we spend billions of dollars building out an infrastructure capable of supporting and recharging electric cars wanting to travel substantial distances? Again, whatever solutions we put in now could end up being obsolete surprisingly quickly.

So while I’m convinced that now is an excellent time for the US to embark on a substantial round of infrastructure investment, I’m less convinced that we should be investing in rail in particular. A smart electricity grid, definitely. Improvements on existing bridges and tunnels, absolutely, including that new tunnel to New Jersey. But I’m less convinced about things like a high-speed rail link between San Francisco and LA. Especially so long as there aren’t any self-driving cars to pick up passengers when they arrive.

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