Intercity Rail Ridership Forecasting and the Implementation of High-Speed Rail in California

This working paper is the first in the CalSpeed series to address the question of the market potential for high-speed passenger rail service in California. Along with construction cost, forecast ridership is the second significant question asked about any proposed high-speed rail system. Indeed, the decision to construct such systems is often portrayed as contingent on such forecasts. For this reason, an examination of the rail ridership forecasting experience is a worthwhile preliminary to the CalSpeed ridership estimates. This first part of the paper focuses on the high-speed rail systems in Europe and Japan and the role that ridership forecasts played in the decision to build the original high-speed rail lines. The European and Japanese situation is then compared to the situation California faces today. The next part draws an analogy between the decision to construct the second-generation rail transit systems in the United States and the decision to construct high-speed rail in California. This part reviews criticism of rail transit ridership forecasting and examines the original bay Area Rapid Transit (BART) forecasts as an illustration of the difficulties involved in forecasting for new modes. Throughout the paper, questions of accuracy and sources of error are addressed as thoroughly as possible. What does the accuracy of past ridership forecasts say about forecasting as a decision-making tool in the public or private arenas? How might the rail forecasting experience benefit a California study? The paper will address these questions and others, and concludes with a discussion of the role that ridership forecasting might play in the decision to build a California high-speed rail system.