Samenvatting
In order to evaluate the effectiveness of an area traffic control system it is necessary to establish a criterion by which the effectiveness can be judged; to measure or to estimate the performance of the control system with respect to this criterion; and to analyse and to interpret the significance of the measurements. Experience of measuring the effectiveness of area control systems in Glasgow, including the comparison of different methods of measurement, the experimental design of surveys, automatic analysis of data and interpretation of results, are discussed.