Maintenance of existing road network infrastructure and expansion of networks with new facilities are two major investment categories in the transportation system. Road maintenance projects optimize the scheduling of maintenance activities so that pavement is in good condition and so that road expansion projects add extra capacity to a road network to improve mobility. The two problems are usually considered separately in practice; however, an integrated approach to these two problems was proposed. The road maintenance problem and the road expansion problem were formulated together as a mixed-integer, nonlinear, bilevel optimization problem with the objective of optimizing overall system performance. A solution algorithm that was based on the generalized Benders decomposition theory, significantly relaxing computational complexity, was proposed. Finally, a numerical case study demonstrated the proposed problem and the algorithm used to solve it. The benefit of the integrated model over models that consider only maintenance or expansion projects was discussed.