Numerous studies have shown the importance of external costs of road congestion, especially when peak-periods appear. But the modeling of road congestion subject to peak-periods generally uses a bottleneck model, without the classical travel-time function used in models without peak-periods. This paper tries to synthesize these models, which are in fact complementary, by reintroducing in bottleneck model this relation which is here considered as a relation between speed and distance between cars. Cost-sensitive demand is also introduced. In this model, the route capacity is not determined in one unique location as in traditional models but is global. This means that a certain number of cars can pass along the route with a given generalized cost (price and time).The results given by this model allow a few qualitative conclusions. The importance of the spreading out of traffic is for instance illustrated by the fact that, starting from a given equilibrium, the generalized cost increases quasi-linearly with the traffic rather than explodingly if we neglect the possibility of spreading out as it is in general the case in operational models. The efficiency of a congestion toll to near collective optimum is otherwise confirmed, but, contrary to bottleneck models, its use raises a redistribution issue. Lastly, it appears important to take in account, in économic studies on roads investments, the additional traffic due to cost sensitive demand.
Through the notion of maritime space, the aim is to show how containerisation has affected the countries of the third-world where its implementation was much slower than on East-West relations. Thus, the globalisation of the maritime space has marginalised developing countries. North-South relations belong to the periphery of the maritime space: they are dependent on its centre formed by a round-the-world flow of goods which links the poles of the Triad. A dynamic study of the strategies developed by shipowners is carried out from the example of the CGM.
The changes undergone by the production system have generated a new conception of the role played by stocks in companies and more generally in the economic system itself.Yet we can wonder whether those economic upheavals have modified the locations of stocking sites. The purpose of this article is to use a geographer’s approach to identify the locations of stocking sites in France (by means of an appropriate indicator) and evaluate the dynamic current of change they experience.
Having realized that transport has become a significantly larger contributor to energy consumption and the environmental degradation, this study aims at identifying its comprehensive mechanism and providing a scenario analysis method to understand the future environmental consequences.The mechanism is investigated on the basis of urbanization, motorization and the environment nexus within the transport domain. Each linkage between the components inside the mechanism e.g. population density and distribution, urban configuration, income level, car ownership, transport infrastructure supply, infrastructure investment level etc., has also been examined empirically. The subsequent attempt is to illustrate and validate the proposed premise on the basis of actual interrelationship among urbanization, motorization and the environment through an analogous approach of equivalent development patterns in four diverse metropolises -namely London, Tokyo, Nagoya and Bangkok- situating at various stages of economic development process and at different points of time.The results of the study contain many-sided meaningful evidences and considerable findings to mechanize and support the presumable sequences of nexus. In addition to transport contributor, other environmental consequences are also analyzed. It is likely that the urban development path of a younger aged metropolis will typically follow the same manner as those of prior elderly aged metropolises but rather at an accelerating rate […]