In the transportation planning for some industrial wastes, in addition to h
auling cost, environmental impact must frequently be considered. A notable
example is transporting waste soil generated by major construction projects
. Adequate transportation planning is particularly important for constructi
on in a metropolitan area. In this study, we present a novel two-phase appr
oach to address the multiple-criteria decision problem. The first phase app
lies the fuzzy analytic hierarchy process to obtain a "composite impedance"
for each road sector where transportation costs, environmental impact, and
traffic congestion are considered in the evaluation. The second phase empl
oys fuzzy mathematical programming to find the optimal transportation netwo
rk based on the fuzzy impedance. An illustrative example is provided for th
e transportation planning for waste soil of the Kaohsiung mass rapid transi
t system construction project. The optimal solutions using the proposed app
roach are compared with the solutions using the conventional shortest-path
approach where minimizing the transportation cost is the only objective.