A bi-level decision support system for uncertain network design with equilibrium flow

•A bi-level DSS for uncertain network design with equilibrium flow.•A risk-averse BDSS to mitigate worst-case travel demand.•A gradient based method to solve a BDSS.•A Stackelberg solution for BDSS.•A real-data road network to demonstrate effectiveness and robustness of BDSS.

A bi-level decision support system (BDSS) is proposed for a normative road network design with uncertain travel demand. A bi-level decision support model with link capacity expansion is developed to simultaneously reduce travel delay to road users and mitigate vulnerability of road network. A tractable solution scheme for BDSS is developed. Due to some hierarchy in decision-making order of BDSS, a bi-level programming is employed. A risk-averse Stackelberg solution is established for a normative BDSS under travel demand uncertainty. Numerical computations are performed using a real-data road network. Computational results indicate that the proposed solution scheme can effectively improve a worst-case performance of BDSS with greater success while incurring a relatively slighter loss of optimality when compared to deterministic solutions at nominal condition. Particularly, our computation results showed that proposed solution becomes more attractive as the realization taken by unknown demand growth factor increases.