The climate impacts of high-speed rail and air transportation : a global comparative analysis

Abstract

Growing concerns about the energy use and climate impacts of the transportation sector have prompted policymakers to consider a variety of options to meet the future mobility needs of the world's population, while simultaneously addressing the impact of these systems on our environment. This dissertation focuses on air transportation and high-speed rail (or "high-speed transportation"), a sector for which demand is projected to grow substantially, and for which infrastructure and vehicle investment decisions are costly and long-lived. This research examines high-speed rail (HSR) and aviation systems in three regions to explore: 1) the historical context of high-speed rail and aviation demand; 2) potential policies that may shape HSR and aviation system demand and their environmental impacts in the future; and 3) individual mode choice between HSR and aviation. The goal of this work is to improve our understanding of demand for these systems and methods to examine their climate impacts. Chapters 3 and 4 provide an empirical analysis of the European experience with highspeed rail and aviation systems. First, we contribute to econometric analyses of air travel demand by examining the impact of high-speed rail on air traffic. Using origin-destination demand data as well as airport demand data for two decades, our econometric analysis shows that the introduction of high-speed rail has resulted in substantial decline in air traffic on short-haul routes, as well as domestic air traffic in nations with high-speed rail infrastructure. Those cities that have higher density experience an even larger reduction in air traffic. However, we find that over this same time period, the expansion of low-cost carriers in Europe has had an even more substantial impact on increasing total air traffic within the European aviation system. Second, we explore cooperation versus competition between high-speed rail and air transportation systems. Through case studies and travel demand analysis, we examine how air-rail connections have formed in Europe, factors that contribute to high utilization of these connections, and their impact on travel demand. We find that although capacity shifts within the air transportation system have occurred as a result of these connections, there are a number of unique factors that contribute to their success. In Chapter 5, we shift our attention to the United States to conduct an integrated analysis of transportation and climate policies. By developing a new model to examine high-speed rail and aviation demand and their environmental impacts under alternative climate and energy policies, we find that the energy and CO2 emission savings of high-speed rail increase substantially when combined with such policies. These savings are primarily due to the relative efficiency of high-speed rail systems combined with a shift towards less carbon-intensive efficiency of high-speed rail systems combined with a shift towards less carbon-intensive electricity generation. The first three analyses assume that price and travel time are the dominant factors influencing intercity travel choice between high-speed rail and air transportation. In Chapter 6, we explore the potential influence of environmental attitudes on individual choices between high-speed rail and air transportation. By conducting an intercept survey in China, we find that rail passengers tend to be more concerned about the environment than those individuals likely to choose air travel. Second, we find that high-speed rail accidents do have a significant impact on future mode choice, and that safety concerns play a significant role in intercity travel choice. This dissertation concludes with an analysis of current policies that influence high-speed rail and aviation in the United States, and their long-range environmental impacts. Integrating our findings from the three regional analyses of high-speed rail and aviation, we make recommendations for future policies that shape these long-lived infrastructure systems. Given likely growth in demand for high-speed transportation in the United States and other regions, our goal is to inform future investment decisions and policies that meet these mobility needs while mitigating their energy and climate impacts.