In this paper, a model able to analyse the seismic behaviour of road network in urban areas, considering interaction between buildings and roads is presented. Damage to buildings and short-term countermeasures, such as propping, can affect roads and even block them, reducing capacity of the road network. Two successive phases are considered. In the first, immediately after the seismic event, emergency services have to reach the relevant buildings. Here, the network topology is of interest. In the second, in the long term, network capacity is not yet completely restored and network demand has to account for displaced people due to unusable buildings. In this case, road serviceability is of interest. In order to consider uncertainties on building behaviour, a probabilistic approach is developed and the network is analysed by means of Monte Carlo simulation. The methodology is applied to the municipality of Potenza (southern Italy) evaluating in the short term, the probability of strategic buildings are not connected and, in the long term, road serviceability.