The countermeasures against the megathrust earthquake along the Japan Trench (Japan Trench earthquake), where the 2011 Great East Japan earthquake occurred, should be taken to enhance the disaster resilience in Japan. In this paper, the resilience of a road network subjected to both seismic and tsunami impacts due to the anticipated Japan Trench earthquake is estimated. The seismic and tsunami fragility curves of a road are developed empirically using the damage data observed in the 2011 Great East Japan earthquake. The individual routes in a road network is calculated based on the developed fragility curves and the hazard intensity of the anticipated Japan Trench earthquake. The resilience is defined as post-disaster traffic-carrying capacity and assessed for each route in a road network based on the failure probability. Finally, the routes which can be used after the earthquake are discussed based on the resilience.