We propose in this paper a receding horizon optimal control strategy for the bimodal urban traffic, cars and public transport. The aim of this strategy is to control the traffic lights durations in order to relieve the traffic congestions in the hole of the network making more for the arcs where the public transport vehicles are present. The bimodal traffic is represented by a linear model. The constraints on the state and control variables are considered within the optimization problem. The numerical resolution is carried out thanks to the active set method. Simulations results are given for a small urban network.