The TNDP consists in seeking a transportation network configuration that minimizes some objectives, subject to the equilibrium constraint.
We could regard it as an environmental cost of the transportation network system, which should be minimized in the optimization objectives of the TNDP.
Similar to a conventional TNDP, the mixed sustainable TNDP can be formulated as a bilevel programming model, in which the upper-level model is the network structure design model and the lower-level model is the user equilibrium assignment model.
This paper documents a method by which the TNDP may be addressed using GIS.
Non-GIS methods used to solve the TNDP can be classified into three categories: (1) constrained optimization models; (2) heuristic approaches; and (3) practical guidelines or ad hoc procedures (Tom and Mohan 2003, Fan and Machemehl 2004).
Many of the optimization frameworks proposed to solve the TNDP are based on the works of Ceder and Wilson (1986) and Baaj and Mahmassani (1991).