In this paper, we study an optimization approach for congestion management for traffic signal control systems via first-order hybrid Petri nets. The traffic signal control problem is represented by the optimal firing sequence problem for the first-order hybrid Petri net (FOHPN). In order to solve large scale problems, the Petri net decomposition approach for FOHPN is developed. The computational results show that the computation time can be reduced by the proposed approach and the outcome of the FOHPN decomposition approach for congestion management.