Delphi Methodology for Economic Impact Assessment

In 1988, the Roads and Transportation Association of Canada (RTAC) funded a research project to provide a look at the road‐funding situation in Canada, the parameters related to it, and its potential economic ramifications at the turn of the century. To do this, a Delphi forecasting approach was chosen, which looked at how the intensity of system use and the costs of building and operating the road system would change in the interval and identified technological, economic, and social factors that might affect road‐infrastructure investment patterns in the future. This paper focuses on the methodology used in the study. The technique worked well, with good response levels from the panel members, reasonable response times, and convergence on the majority of questions within three rounds of questioning. Microcomputer technology was exploited to simplify older manual methods for processing such data. The technique offered significant advantages over quantitative forecasting through its ability to reach consensus on the validity of forecasts, basic assumptions underlying them, and potential key developments that might result in changes to them.