We studied the following organization for the letter and parcel pick-up and delivery problem in an urban environment: the working day is divided in time periods during which each vehicle starts from a sorting center, travels to a precise area of the region, picks up and delivers letters and...

We present an overview of continuous approximation models that have been developed for freight distribution problems. A taxonomy of six classes is used to differentiate the problems and a brief review of each paper is provided. This paper stresses important principles and key results from the...

Railway planning is a complex activity which is usually decomposed into several stages, traditionally network design, line design, timetabling, rolling stock, and staffing. In this paper, we study the design and optimization of train timetables for a rail rapid transit (RRT) line adapted to a...

This paper introduces the fleet size and mix pollution-routing problem which extends the pollution-routing problem by considering a heterogeneous vehicle fleet. The main objective is to minimize the sum of vehicle fixed costs and routing cost, where the latter can be defined with respect to the...

The Time-Dependent Pollution-Routing Problem (TDPRP) consists of routing a fleet of vehicles in order to serve a set of customers and determining the speeds on each leg of the routes. The cost function includes emissions and driver costs, taking into account traffic congestion which, at peak...

In this paper we study the problem of locating a new station on an existing rail corridor and a new junction on an existing road network, and connecting them with a new road segment under a budget constraint. We consider three objective functions and the corresponding optimization problems,...

This paper presents a model and an algorithm for the design of a home-to-work bus service in a metropolitan area. This type of service must display an equilibrium between conflicting criteria such as efficiency, effectiveness, and equity. To this end, we introduce a multi-objective model in...

This article describes a tabu search heuristic for the dial-a-ride problem with the following characteristics. Users specify transportation requests between origins and destinations. They may provide a time window on their desired departure or arrival time. Transportation is supplied by a fleet...

Mailbox collection is a complex and costly operation in most postal services. The authors recently undertook a study aimed at improving this operation at the Canada Post Corporation (CPC). This paper describes an improvement to the clustering and routing algorithm currently in use. Various...