A multiobjective approach to transportation network design

A two-layer transportation network design model with three objectives is introduced. The objectives are: the minimization of the primary path length (or traveling time) from a predetermined starting node to a predetermined terminus node; the minimization of the total distance traversed by the demand to reach a node on the primary path; and the minimization of the total network construction cost. The problem is initially formulated as an integer linear programming model. A combinatoric solution which would be suitable for small networks because of the large size of the subtour breaking constraints is presented. The method produces efficient solutions according to the objectives mentioned above. The criteria of alternate transportation facilities, environmental concerns, and socio-economic structure are included for these efficient solutions. By using Zeleny´s ideal point approach the best compromise solution is then selected. The results of a numerical example are also given. Some potential applications of the model include the planning of a new highway or rapid transportation system and the design of an energy distribution system.