Rational intervention in human activity systems such as transportation planning can be achieved through effective citizens' participation. Soft systems methodology provides one such framework and is an inquiring system used to tackle ill-structured problem situations in planning. It enables its users to learn their way to taking action and to improve a problem-ridden situation. This methodology marks a paradigm shift in dealing with complex planning problems. A soft system methodology, formulated by researchers at the University of Lancaster, United Kingdom, is· described and this methodology is applied in a case study to demonstrate how it can be used in citizens' participation as applied to transportation planning. This methodology has proved to be effective and easy to use.

Recent years have witnessed an increase in citizen participation (CP) programs, although the overall record of success has been lumpy. Knowledge of CP has also increased over time, and the Advisory Commission on Intergovernmental Relations has identified over 30 different forms of CP used in the United States (1).