Events. Events are the scenarios or states of the environment not under the control of the decision maker (that may occur). Uncertainty is measured in terms of probabilities assigned to the events. Measurement of uncertainty for each mode of transport , intermodal transfer and other nodal activities is done via a confidence index . This confidence index is based on a five point type scale: (1) = Almost no confidence; (2) = not very confident; (3) = fairly confident; (4) = confident, and (5) = very confident.