The rising car usage deriving from growth in jobs and residential population causes airpollution, energy waste and consumption of people’s time. Public transport cannot be theonly answer to this increasing transport demand. Carpooling, which is based on the ideathat sets of car owners pick up colleagues while driving to or from the workplace, hasemerged to be a viable possibility for reducing private car usage in congested areas. Itsactual practice requires a suitable information system support and, the most important,the capability of effectively solving the underlying combinatorial optimization problem.This paper describes an ant colony algorithm based hybrid approach (HAC) for solving themulti-destination carpooling problem. Experiments have been performed to confirm theefficiency and the effectiveness of the approach.

This paper addresses a Three-Dimensional Loading Capacitated Vehicle Routing Problem(3L-CVRP) which combines a three-dimensional loading problem and vehicle routing problemin distribution logistics. The problem requires the combinatorial optimization of afeasible loading solution and a successive routing of vehicles to satisfy client demands,where all vehicles must start and terminate at a central depot. In spite of its clearpractical significance in the real world of distribution management, 3L-CVRP in literatureis very limited for its high combinatorial complexity. We solve this problem by a hybridapproach which combines Genetic Algorithm and Tabu Search (GATS). Genetic algorithm isdeveloped for vehicle routing and tabu search for three-dimensional loading, while thesetwo algorithms are integrated for the combinatorial problem. We computationally evaluatethis hybrid genetic algorithm on all publicly available test instances, and obtain newbest solutions for several instances.

In this paper we consider the operational planning problem of physical distribution via a fleet of hired vehicles, for which the travelling cost is solely a function of the sequence of locations visited within all open delivery routes, while vehicle fixed cost is inexistent. The problem is a special class of vehicle routing and is encountered in the literature as the Open Vehicle Routing Problem (OVRP), since vehicles are not required to return to the depot. The goal is to distribute in an optimal way finished goods from a central facility to geographically dispersed customers, which pose daily demand for items produced in the facility and act as sales points for consumers. To solve the problem, we employ an annealing-based method that utilizes a backtracking policy of the threshold value when no acceptances of feasible solutions occur during the search process. Computational results on a set of benchmark problems show that the proposed method consistently outperforms previous algorithms for solving the OVRP. The approach can serve as the means for effective fleet planning in real-life problems.

This paper presents a heuristic column generation method for solving vehicle routing problems with a heterogeneous fleet of vehicles. The method may also solve the fleet size and composition vehicle routing problem and new best known solutions are reported for a set of classical problems. Numerical results show that the method is robust and efficient, particularly for medium and large size problem instances.