Abstract: A data processing method (100) for synthesizing in real time customized traffic information for a user who wants to reach a destination position from a departure position, the data processing method (100) comprising the steps of: —obtaining (103) data which define a topological graph, said topological graph being an oriented graph containing information on the connection between segments of a road network, said topological graph comprising nodes which represent points of connection between two adjacent segments and arcs which connect nodes and which correspond to road or carriageway segments; —generating (104) data which define a routes graph (Gp), the routes graph (Gp) being a subset of the topological graph, having a departure node (10) associated with the departure position, a destination node (20) associated with the destination position, intermediate nodes between the departure node (10) and the destination node (20), arcs (1-5) which connect the nodes of the routes graph to one another, the generating s