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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I had never heard of the Platoon, it seems like a pretty good concept, but it seems that it could be so hard to implement. All those cars need to have the same smart system installed, and there has to be a Platoon Driver going that route, and you have to time it perfectly so you can follow the line. I wonder what will happen when people who are not part of the platoon will tailgate those who are, and people who want to join the platoon can’t because there is someone with a different type of car on their spot?

In regards to the LA – SF high-speed rail I don’t think is a bad idea. After riding from Gare du Nord to London, I totally realize that we need something similar over here. TSA makes people miserable and makes us waste too much time on the airport, and driving from SF to LA is definitely a pain in so many ways: Too long a ride, you end up putting too many miles on your car and during peak hours, the flow of traffic is so slow that you end up bald after pulling all your hairs.

Posted by Engels | Report as abusive

It’s always interesting to me that rail vs. roads discussions typically focus on moving people rather than freight.

As a result, there’s no mention that here in the U.S. we have a quite good freight rail system. In the U.S. rail moves a higher percentage of freight tonnage than rail does in Europe – partly due to geography, but also because the European freight rail market is fragmented and includes a lot of state-owned players. U.S. freight rail is a profitable, private system that operates without large government subsidies, and it’s generally ignored in comparing transportation systems across countries.

Posted by realist50 | Report as abusive

I’ve heard a lot of musing about what driverless cars mean for the future, particularly from the Economist, and I’m still very skeptical. These visions often have speculation that people will stop owning cars because it will be possible to hire a random car on demand, but this is already true in urban areas (with taxis and car-sharing). Many people in cities own cars anyway for practicality, the ego boost, and sometimes economic reasons. Cars are very much aspirational items, otherwise most people would be driving subcompacts sufficient to get them from point A to point B. I don’t see this changing any time soon.

There are other ways the vision doesn’t make sense. If the technology really did become pervasive and people really did stop owning cars individually, the main use for cars would still be commuting during peak hours. To support this, the fleet would have to be nearly as large as it is today, and most vehicles would sit idle during the work day. Peak hour congestion would still be a big problem, whereas rail handles large volumes of people more gracefully. If the fleet stays almost as large as it is today, sharing driverless cars will necessarily be almost as expensive as individual car ownership, providing little incentive for people to give up their cars. People who can’t afford to travel by car or choose not to spend the money would be left with still-mediocre public transit infrastructure.

Also, most of the US probably isn’t urban enough for this kind of thing to be viable. I could see it working in a few big cities, but those are places that already have car-sharing and lots of taxis. Both are too expensive for more than occasional use, and I’m not convinced that self-driving cars would do much to lower the costs. Mass transit will continue to be the primary mode of transportation in big cities, and it would be tragic to keep underinvesting in it.

Posted by aaron_l | Report as abusive

I’m as big of a proponent of electric cars as anybody, and I think self-driving ones would be a boon to society. That being said, I can’t agree with Felix that they would be better for trips like LA-SF than high speed rail. I have trouble believing they would be more energy efficient, and the fact that they are privately funded by users instead of public financed by the government doesn’t make it a better option (only a more likely one in the US).

If cars can be improved so much that they challenge the efficiency of trains, it’s likely that trains can also benefit from the same technological advances, and maintain their huge economic and energy efficiency over cars.

There is no justification for public subsidies for air travel over these short haul routes, yet that is what we have been doing. And even if self-driving electric cars were available, unless they also drove at 200 mph, many people would still prefer air or trains over them, for the simple reason they don’t want a 6 hour trip. So the question isn’t whether we use trains or cars for these 300-1000 mile trips, but rather trains or planes.

Posted by KenG_CA | Report as abusive

Do smart cars and platoons ummm, brake for dogs?

Posted by samadamsthedog | Report as abusive

I think you might be getting cabin fever mate. What’s next – replacing container ships by a platoon of computer controlled yachts?

Posted by dsquared | Report as abusive

So if you currently have to own your own car in order to commute to work (or some other regular task), then you have to pay a lot of fixed costs in terms of the vehicle itself, providing it with parking when not in use, and so forth. But your marginal cost for then also using your personal car for other more occasional tasks is going to be relatively low. So, for example, you might well not have bought a car for just this reason, but now that you have one anyway, you might use it for certain intercity travel needs, instead of using an alternative train, bus, plane, or so on.

With a carsharing model, you don’t have to pay all of those fixed costs on your first necessary use. So your cost barrier to using a car on that first use is much, much lower. Still, those categories of costs are still present, and they have to be spread out to users somehow, usually on some sort of per-unit-of-use basis. The reason this can be beneficial overall is that the everyone-owns-their-own-car model involves an awful lot of waste in these areas, so eliminate that waste and even after paying your fair share of those costs you can come out way ahead.

OK, so now imagine driverless cars allow universal adoption of carsharing. When deciding if, say, you want to use your carsharing service for occasional intercity travel rather than an alternative mode, you will likely now have to choose whether or not to pay what once were fixed costs under the old system, but now are variable costs under the new system. In other words, the “I have a car anyway” reasoning is no longer really applicable.

I don’t know how this will all shake out, since it really comes down to which intercity technology is most efficient in any given case, and I can see some gap-closing coming from driverless technologies for cars (and also some fundamental inefficiencies remaining, such as those arising from the need for the cars to be capable of independent operation, even if for intercity purposes they are in a “platoon”). But I do think it is very important to keep in mind that these cost calculations look very different when the once- fixed costs are redistributed as variable costs.

And in fact, it might be telling that while lots of people do use taxis for local travel (and what are driverless cars besides just much cheaper taxis?), they are not so popular for intercity travel, and there might be good reasons for that observed split in functions which will persist even when driveless cars (aka cheap taxis) replace personal car ownership in serving a bunch more local travel needs.

Posted by BrianTH | Report as abusive

I had the same thought as KenG: that the self-driving car described here is a competitor to municipal and metropolitan transit (particularly driving and light rail, but also cycling, which would no longer be the fastest way of going .5 to 3 miles in lots of cities). But not intercity rail going 120mph+.

Posted by bschmidt | Report as abusive

“Especially so long as there aren’t any self-driving cars to pick up passengers when they arrive.”
Don’t limit your thinking.
Think ZipCar + train + ZipCar.

Posted by davebarnes | Report as abusive

” Improvements on existing bridges and tunnels, absolutely, including that new tunnel to New Jersey.”

Now you’re just being a bi’atch, Felix. Stop rubbing it in that we have a Governor who is more determined to prepare himself to run the nation into the ground than run the state.

Posted by klhoughton | Report as abusive

Highspeed rail is more of a substitute for short-haul flights.

Should do everything where appropiate- self driving cars won’t solve the bottleneck such as Holland tunnel. Maybe self-driving car to the train or bus rapid transit station then back to self driving car.

Posted by lyang | Report as abusive

So, how does the liability thing shape up?

What, if any, licence do I need to sit in an autonomous vehicle and who is going to jail if that car runs over some grandma?

Posted by emu | Report as abusive

You had me until you talked about “car-sharing”. First of all, if car sharing were desirable or feasible, we would be doing it now .. whether the car drives itself has nothing to do with it. But mainly .. I do not know ONE person who does use his or her car as mobile storage unit/purse/safety zone from social norms and the madness of crowds. My car stinks and I like it that way .. I also like to know that when I can’t find my wallet it is almost always because I left it in the car.

Posted by Carbona | Report as abusive

When surveyed on the matter I always say I am against public transportation even though I am not and for pretty much the same reason I side on the side of climate-change denying politicians. Public transportation is a wonderful and needed supplement to private automobiles .. but support for public transportation is invariably used to support the idea of it supplanting the private auto. And that idea is supported mainly by those who either do not have spouses and teenage kids or do not allow those family members a say on what trips and errands need to be made.

Posted by Carbona | Report as abusive

bring back the horse & buggy….

Posted by rikfre | Report as abusive

Spot on we need rail’s efficiencies and road’s flexibility – particularly in places like China and India where the stats on private car takeup are mind blowing and new superhighways clog the day they open. I wonder if the author has seen the TEV Project? It’s a non-commercial project that combines a lot of the technologies mentioned in this article, with the addition of direct electric power to EVs so they can go indefinitely without stopping to charge. Zero emmisions. I would link to their website but I don’t want to look like spam! I think in future the lines between road and rail, and public and private transport are going to blur.

Posted by SimoneT | Report as abusive

Mr. Salmon,

At the beginning of your essay, you said that “the best blog posts…are the ones which change your mind.”

Based upon that criterion, this piece is an abject failure.

To put it another way: if your view of our collective transport future, replete with its burgeoning suburbs, is accurate, I hope I’m dead before it arrives.

Garl B. Latham

Posted by gblatham | Report as abusive

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