Distributed control mechanisms have been studied in past decades in different application areas. Currently, multiagent systems are a popular topic also in ITS systems, where numerous approaches to distribution of system intelligence are being tested. One of the main problems in distributed control, however, remains the guarantee of reaching the global optimum -- while most of the applications perform sufficiently well, there is no way to tell that they cannot perform even better, or that they may fail under certain operating conditions. Luckily, for certain control paradigms such guarantees may be given. In this paper we study two approaches to distributed control, namely distributed LQ control and distributed non-lonear control using COBYLA algorithm, and apply them to urban traffic control scenario. We show that the convergence conditions are met and results achieved with distributed control converge to those of centralised control mechanisms.