A couple of months ago, Frank wrote a blurb about the Obama administration’s commitment to legalize European passenger train designs, which today are effectively prohibited by Federal Railroad Aministration regulations, by 2015. He chose an illustrating photograph which represents, I’m sure, exactly the kind of thing most Americans think when they hear “European train”, namely a picture of Spain’s AVE high-speed train between Barcelona and Madrid.
Now, there’s nothing wrong with that photograph, or that thought: Europe’s high-speed rail services (AVE, TGV, Eurostar, etc.) are indeed wonderful! The FRA modifying its rules to legalize European train designs in the US could make American high-speed services faster, much cheaper to build, and more environmentally friendly, because American trains will no longer have to be built to a completely unique crashworthiness standard, girded with battleship-like quantities of steel. That’s a wonderful and long-overdue advance in itself, but I’m going to argue that cheaper high-speed trains are not the most exciting technology this rule change could unlock.
Europe’s high-speed trains are the icing on a tall cake of public transport, which begins, at a local level, with generally-excellent local bus service, rapid transit in medium to large cities, and extensive high-capacity subway and Metro systems in the biggest cities. At a larger scale, cities and large towns are connected by regional passenger rail lines that run all day and late into the evening, with coach services extending to smaller towns. Most of those regional lines will never carry enough people to justify the massive expense of high-speed rail, but they’re well used, and taken together, carry far more trips than the high speed lines.
The success of the high-speed lines could not happen without the connectivity provided by regional and local services, not to mention the higher-density, less-car-focused land uses they have facilitated for more than a century. These regional services make extensive use of a technology that, thanks to the FRA’s over-zealous regulation, had hitherto occupied only a niche role in American passenger railroading: the Diesel Multiple Unit train.
DMUs are diesel-powered versions of their cousins, Electric Multiple Units, of which American light rail vehicles are an example. Each carriage has its own propulsion system, and trains can be made up of as many or as few as are needed to meet demand. DMUs are typically slightly larger than a light rail car, and seat 100-200 people; the photo above is an example European DMU, a Stadler 2/6, on Austin’s Capital Metrorail Red Line. That design was previously only usable on track not shared with freight trains or other traditionally-constructed mainline passenger trains, but after 2015, it will be legal to operate it on shared track. This is a very big deal, because much of the existing urban and suburban rail trackage in the US has at least some freight or mainline traffic.
This rule change makes passenger rail financially viable and environmentally justifiable in markets where it would never be possible to fill up a full-size locomotive-hauled train; it allows trains to scale down. A local example of a market DMUs could serve post-2015 would be Sounder North, a commuter rail service that has struggled with low ridership, currently attracting (pp. 19 & 20) less than 125 riders per trip in the mornings, and 150 per trip in the evenings Sound Transit currently runs the shortest trains allowable under federal rules, a locomotive and two bi-level carriages, providing just under 300 seats, half of which go empty. A pair of Stadler 2/6s, with about 100 seats each, or a Stadler 2/8, a slightly larger DMU which seats about 170, could comfortably carry that load.
To get a sense of the economic and environmental cost of America’s overbuilt trains, let’s look at a simple number, the weight of the trains, taking Sounder North as an example. To a first order approximation, the environmental and economic cost of building and operating a vehicle (of a certain type of fuel) is proportional to the amount of metal that goes into it. A three-car Sounder North train weighs about 240 metric tons (50 t carriages, 120 t locomotive), while the Stadler 2/8 weighs 79 metric tons. So, roughly speaking, we could comfortably move Sounder North’s passenger load with a third of the fuel and materials we use today. This would do much to bring down Sounder North’s painfully high cost per boarding; to boot, a DMU train would almost certainly accelerate faster, ride more smoothly, and be quieter to the neighbors. DMUs on this line could be a huge win.
I should be clear that I’m not advocating that we build a nationwide passenger rail network of the kind found in Europe. In much of the interior of the country, the population is far too sparse to pull in significant intercity transit ridership, population centers are two far apart to allow trains to easily compete with flying, and half a century of freeway building has created a network much more direct than the railroads of the 1900s. What I am arguing is that in those places where regional density exists, DMUs could allow services to exist that otherwise wouldn’t, and that is potentially revolutionary. Later this month, I’ll have a detailed post on how we could apply this idea locally, but I’m sure readers will chime in with their ideas of where DMUs could be useful.