Abstract : This thesis aims to develop algorithms and models for optimizing itineraries in road networks. The first part of this work treats the problem of intercepting a mobile in a graph. In this context, the goal is to compute the optimal path to reach a moving target with a known itinerary. This problem is studied for different situations (one pursuer/one target and several pursuers/several targets) and for different types of graphs (time-independent graphs and FIFO graphs). For each case, an algorithm is suggested and its optimality is proven. Moreover, simulations are conducted to check the algorithms efficiency in terms of execution time. In the second part of this thesis, a new class of time-dependent graphs is defined : the time-dependent interval graphs. The distinctive feature of these graphs is that the edge weight is time-dependent and it is defined by an interval. For this new class of graphs, the shortest path problem is studied. This problem can be viewed either as mono-objective optimization problem or as a multi-objective optimization problem. For each case, the problem is formulated and approaches for resolution are proposed.