The social, economic, and environmental benefits and costs of implementing high-speed ground transportation (HSGT) service could offset some of the investment required for implementation. These potential impacts are called "externalities" or "external benefits and costs" because they are external to the economic market for HSGT service. The methodology framework used to project external benefits and costs of HSGT for the rail commercial feasibility study is described. The externalities are defined and classified, and the general approach to estimating externalities and applying the resulting methodologies is discussed. The principles of two key methodologies for estimating reduced delay to airport and highway users from diversions to HSGT are summarised. A quantitative overview of the results is presented for the California, Chicago hub, and Northeast corridors. Social benefits and costs were found to be an important part of the potential benefits of high-speed rail. Except for some low-speed technologies, only the combined public and user benefits exceed costs. The "traditional" time-saving benefits dominate the public benefits, comprising 92 to 98 percent of total public benefit. Environment (emission) benefits went down with rail speed because of proportionately lower diversions from highway and higher diversions from air with higher rail speed.
Abstract