A solution of the bicriteria vehicle scheduling problems with time and area-dependent travel speeds

This paper is concerned with the bicriteria vehicle scheduling problem with time and area-dependent travel speeds, in which two conflicting objectives are explicitly treated and the travel speed between two locations depends on the passing area and time of day. The two objectives are the minimization of total vehicle operation time and the minimization of total weighted tardiness. First, I construct a mixed integer linear programming formulation, and present a heuristic named PC-saving algorithm (bicriteria-saving algorithm) that builds the vehicle schedules based on the savings computed. The results of computational experiments show that the heuristic is very successful on a variety of test problems. Finally, I propose ran interactive Scheduling computer system based on the PC-saving algorithm to deal with real complexity and subjectivity in the vehicle scheduling process. (C) 2000 Published by Elsevier Science Ltd.