The increasing awareness of the importance of the wider objectives of traffic management and control has led to the work described in this paper. The aim of the study of which this is a part is to develop a flexible signal controller which may be configured so that it embodies the objectives appropriate for the situation in which it is to be used. This paper describes the investigation made into the feasibility of optimising a prototype fuzzy logic signal controller with respect to several criteria simultaneously. The controller's sensitivity to changes in the membership function parameters was demonstrated and it was not possible to minimise simultaneously even the limited set of performance measures explored (travel times and emissions). These results indicate that a multiobjective genetic algorithm (MOGA) optimisation technique is appropriate for further research.