We propose a new approach of cellular automata models, based on a graph frame, which allows the modelling of irregular and dynamic neighbourhood of spatial entities. The Remus model permits the computation of a graph representing the buildings and the transportation network (the urban graph), and thus the calculation of the network distance-time between buildings. This model allows the extraction of various graphs, including the functional graph of the network-time-distances between buildings, and the neighbourhood-relationships graph which represents the network-neighbourhoods according to a certain time-distance-threshold and a given transportation mode.