A BILEVEL PROGRAMMING ALGORITHM FOR EXACT SOLUTION OF THE NETWORK DESIGN PROBLEM WITH USER-OPTIMAL FLOWS

In transportation planning, a large class of problems is characterized by multiple levels of decision making. This paper shows how to formulate such problems as bilevel programming models, and proposes solution algorithms for evaluation. For the Transportation network design problem, the paper shows that this model can be solved exactly for networks with a few hundred nodes. A linear bilevel programming model of the network design problem is formulated with user-optimal driver behavior and continuous link improvement variables. This formulation leads to insights into the type of model appropriate for the network design problem with user-optimal driver behavior. The corresponding algorithm can be used to solve exactly network design problems with moderate sized networks. Refs.