As Americans, we often pride ourselves on being the inventors of the biggest and best. We’re obsessed with having the largest and most powerful of everything, and from super stores and SUVs to second homes and cheeseburgers we often take the cake. By our definitions, all of Europe drives small cars and a French entrée is an appetizer. So why on Earth do the fastest trains belong to China, Japan and the EU? In this regard, our loyalty to the automobile has put us decades behind other nations in harnessing this high-speed, high-tech mode of transportation.
High-speed rail has been touted by many as the way of the future, providing mass transit for growing populations while countering today’s carbon-intensive transportation. In the United States, high-speed rail is categorized in three groups, determined primarily by speed: Emerging High-Speed Rail (top speeds of 90-110 mph); Regional (110-150 mph); and Express (over 150 mph). Currently, only one line in the country qualifies, Amtrak’s Acela Boston-New York-Washington, DC route. Only a small portion of the route accommodates the train’s top speed of 135 mph, and, including stops, the entire three-point trip averages a pedestrian 68 mph. In contrast, the high-speed line between Seoul and Pusan, South Korea nearly doubles Acela’s speed, achieving an average of 120 mph. Even faster trains than these abound across Europe and Asia, but the question remains: Are they an innovative environmental improvement or simply a costly show of technical savvy?
As with so many would-be-silver-bullet technologies, the answer here is “It depends.” One way to compare the environmental impacts of different modes of transportation is to use a metric called passenger miles. This incorporates the number of passengers and the distance over which they are being moved to come up with a single number that applies to all modes. A 2006 study by the Center for Clean Air Policy determined that, for a high-speed train similar to those being considered for use in California, the average emissions of carbon dioxide per passenger mile were half of those from automobiles, and 40 percent of those from airplanes (0.26 lbs of CO2 for high-speed rail compared to 0.53 lbs for cars and 0.62 lbs for planes). This metric is tricky because it’s dependent upon occupancy – a train only ten percent full, for example, emits far more emissions per passenger mile than an average car (determined by the Department of Transportation to hold 1.6 passengers on average). This study used the DOT number for automobiles and 70 percent occupancy for the high-speed trains, a number that would also ensure financial success for the planned system in California. And although rail is not a primary mode of transportation for many Americans, international examples suggest that ridership can skyrocket once high-speed lines are developed.
A more holistic recent study by engineers at Arizona State University and the University of California, Berkeley concluded that high-speed rail “has the potential to reduce…impacts to people and the environment, but must be deployed” in a way that is consistent with environmental goals. The authors listed ridership and the energy sources relied on by the trains as critical to achieving significant improvements over current modes of transportation. In February 2011, Vice President Biden laid out an ambitious plan to develop high-speed rail in the United States. While the proposal immediately met firm opposition from politicians and transportation lobbies and is currently at a near stand-still (except in California), the proposed routes reflect a goal of replacing long car trips and short- to medium-length flights. These are the distances over which high-speed rail can save the most time and potentially attract the highest ridership. We know that more passengers per train leads to a greater reduction in emissions, particularly since the additional passengers would presumably have driven or flown instead. (By this same logic, carpooling is still a good idea). In addition, high-speed rail is a technology whose environmental impact can be reduced once it has been developed by attracting more riders and, depending on the technology, by increasing renewable energy’s contribution to our electricity grid.
To be sure, high-speed rail is still associated with a host of environmental impacts, and while it could lead to significant reductions in greenhouse gas emissions, it is far from a carbon-free technology. Those who boast these claims simply haven’t read – or have chosen to ignore – the facts. Opponents of high-speed rail don’t seem to be turning to the data either. As an entertaining example, one prominent conservative commentator claimed that the “real reason for progressives’ passion for trains is their goal of diminishing Americans’ individualism.” Conspicuously absent from current proposals are the trappings of a conspiracy to eliminate highways and shutdown the auto industry, but this and other criticisms never had more than a distant relationship to logic. It’s clear that high-speed rail has become highly politicized, and, as with many other issues that have suffered this fate, facts and reason (and, ultimately, the pubic interest) have gone by the wayside in favor of shortsightedness and scorekeeping.
The Verdict: High-speed rail is not our answer for eliminating GHG emissions from the transportation sector. Done properly, however, it can significantly offset environmental impacts from passenger cars and air travel. Having a serious discussion about how best to develop high-speed rail is important, but proponents and opponents will both need to stick to the facts.