Cameroon and Ivory Coast accompanied the devaluation of CFA franc (January 1994) by reduction of taxation intended to contain the rise of the prices and, in the field of transport, by policies intended to restore the state of the road network and to return the haulage sector toward a more market. Investigations into the prices and costs of haulage carried out in 1988, before the devaluation, and 1996, 2 years afterwards, make it possible to measure the reduction of the prices in currencies of this service and to appreciate the evolution. The noted drop in the haulage prices in currencies, is mainly related to the reduction on the taxation of imported production factors (vehicles, fuel, spare parts). Two effects are worrying for the system sustainability: an ageing of the park, related to the carrier incapacity to purchase new vehicles, and an increase in average tonnage by loading, well beyond what the roadways can normally support.
In a context where a lot of European conurbations are trying to reduce or to contain car use in urban areas for environmental or economic reasons, this article aims at assessing the contribution of certain major trends to the evolution of modal split between public transport and car. The objective is to quantify these contributions. We examine the effect of urban sprawl and car ownership growth on the share of trip market between public transport and car. In the Lyon Conurbation, during each of the last two decades, the development of localisation of trips explains a decrease of 6 to 9% of the share of public transport depending on decade and study area ; while the increase in car ownership (with a fix spatial structure of flow) explains a smaller decrease between 1 to 4%. This quantification can inform decision-makers about probable changes in the market share of public transport and the importance of certain factors in these changes. It makes it possible to construct more realistic modal split scenarios and assess the scale of the effort that is required if only to maintain the car in its present position with a view to achieving sustainable development.
Using a theoretical framework in terms of "proximity" and an industry survey in the North of France, this article analyses the role of transport and logistics in contemporary production systems and demonstrates the decreasing role of transport constraints such as accessibility. In particular, the diffusion of Just-in-time (JIT) systems cannot be correlated to the quality of access to the transport system. By developing a typology of modes of circulation of firms, based on the concept of "world of production", the article explores the variety of firm strategies aiming at flexibility, quality and reliability of the circulation of products. Four types of circulation can be identified (industrial, flexible, professional and immaterial), distinguishing the nature of strategic flows, the organisation of transport and logistics, the use of EDI and, more generally, the forms of proximity. We finally conclude that there is no convergence towards a single mode of production nor a single mode of circulation.
The problematics of sustainable development allow us to understand negative transport externalities such as waste that exceeds the assimilative capacity of both the natural environment and man. They lead to a comparison between damage costs, in non sustainable situations, and damage avoidance costs incurred in attaining sustainability. Such comparisons require a standard method for evaluation. This paper builds such a method from the fundamental theories of Piero Sraffa and David Ricardo. To Sraffa's reproduction equations, it adds waste recycling equations and extends Ricardo's rent theory to some critical natural assets other than land. It then applies these theoretical conclusions to the concrete negative externalities of the Paris region transport system. With respect to the greenhouse effect and regional air pollution, avoidance costs are found to be inferior to damage costs, rendering sustainability economically efficient.