Estimating investment requirement for maintaining and improving highway systems

This paper presents an integrated and robust approach for estimating the investment necessary to maintain or improve the future levels of service and pavement conditions of facilities in a highway network. The approach is based on robust optimization and assumes that future travel demands and facility conditions are uncertain but confined to an ellipsoidal uncertainty region and traffic flows on the underlying network are in user equilibrium. The problem is formulated as a mathematical program with equilibrium constraints and solved via a cutting plane algorithm. Numerical results from the Sioux Falls network suggest that the approach can potentially address realistic networks.