Road network functionality after an earthquake is a crucial aspect for an already struck community. In particular, bridges are susceptible to earthquake-induced damages and to lengthy restoration works. This may lead to severe and unexpected disruption of traffic. In this paper, a model for the assessment of the seismic resilience of a road network is presented. The proposed model permits us to evaluate the earthquake-induced perturbations to the functionality of a network in terms of transportation capacities, traffic congestion, and travel times due to bridge damages and subsequent restoration interventions. The evolution over time of the functionality of the network is studied by means of a multi-stage approach describing the evolution of the situation in terms of reducing the normal pre-earthquakes transportation capacities. The methodology has been illustrated with reference to a hypothetical case study, a road network composed of 14 nodes and 31 links.