Pavement management systems (PMSs) are increasingly important tools in the decision-making processes regarding the maintenance and rehabilitation of road pavements. A new optimization model to be used within network-level PMSs is presented in this paper, together with a genetic-algorithm heuristic to solve the model. The model assumes decisions to be segment linked, thus overcoming the principal drawback of the widely used Arizona PMS. The objective of the model is to minimize the expected total discounted costs of pavement maintenance and rehabilitation actions over a given planning time span, while keeping the network within given quality standards. The model was applied to three test problems involving the road network of Coimbra, the third-largest Portuguese city. The results obtained for these problems clearly indicate that the model is a valuable addition to the road engineer’s toolbox.