Transport reviews prize

The transport problems that urban centres now face (as regard congestion, the environment and public deficits) have led to an examination of competition in the sector. Some countries have moved towards the deregulation or privatization of urban public transport, influenced by developments in the theory of contestable markets. These analyses could potentially provide a means of increasing the efficiency of public services and, hence, public transport. However, the authors do not feel that they can deal with the full extent of the problem. Particularly in urban areas, there is a need nowadays to examine the issue of competition between the passenger car and public transport, especially from the pricing angle. In France, decades of policy strongly influenced by a preference for the car have prevented this problem from being a central concern for researchers and decision-makers. The approach to the problem has mainly been centred on increasing urban supply to meet demand better. However, a failure to consider pricing, and the subsidization phenomena that can occur as a result, affects the shape of supply systems. Pricing, through its action on demand, acts on supply by increasing or reducing its potential profitability. 'Snowball' effects can, therefore, mean that slight underpricing results in the domination of one transport mode. These effects have been revealed in particular by work in the new field of network economics. The example of the Lyon conurbation shall be used to illustrate the case, which is that car travel is underpriced. The basis of the exposé will be a detailed analysis of the externalities associated with the car, i.e. the costs of car use and the revenue it raises for the community. The second part of the paper is a study of several urban travel policies in Europe (France, UK, Switzerland, Italy) to show the 'effects' of this underpricing. Where supply has followed the pressure of demand, the dominance of the car has been reinforced. However, in cities, particularly in Switzerland, where supply has been restricted, this dominance has been considerably moderated. On the other hand, it can be seen from the French example that taking strong action to improve public transport is not in itself sufficient to increase usage. Several lessons can be learnt from this work. First, it is shown, if it was still necessary to do so, that the problems of urban travel require a comprehensive and coherent approach. Modal policy must, therefore, be assessed with reference to the entire transport system. Next, in connection with the issue of regulation, it is important to consider the issue of competition in urban areas, and not only competition between public transport operators, but also (and even above all) competition within the entire system of personal and public transport. Finally, with regard to pricing, the ratchet effects that benefit the car as a result of its underpricing in urban areas need to be studied.     

KERFIX, a time-series station in the Southern Ocean: a presentation

Between January 1990 and March 1995, the research project KERFIX undertook the first regular noncoastal multiyear acquisition of parameters related to the carbon cycle in the Southern Ocean at a time series station located at 50°40′ S–68°25′ E, 60 miles southwest of the Kerguelen Islands. The objectives of KERFIX are (1) to monitor the ocean/atmosphere CO₂ and O₂ exchanges and to understand which processes govern these exchanges (2) to observe and interpret the seasonal and interannual variability of the production, flux, decomposition and dissolution of carbon and associated elements at this location. In addition, micropaleontological studies describe the present and past flux dynamics in this oceanic area, to improve the knowledge of the transfer functions of some oceanographic proxies. This paper presents a survey of the KERFIX program: scientific objectives, organization of the field operations and some main results obtained since the beginning of KERFIX program, as well as the results of the temporal evolution of hydrological, chemical and biological parameters.     

Distributions of oxygen and carbon stable isotopes and CFC-12 in the water masses of the Southern Ocean at 30°E from South Africa to Antarctica: results of the CIVA1 cruise

This study presents oceanic distributions of stable isotopes (δ¹⁸O of water and δ¹³C of ΣCO₂) and CFC-12 from samples collected during the CIVA1 cruise (February/March 1993), across the Southern Ocean, along a meridian section at 30°E, from South Africa (44°S) to Antarctica (70°S). The isotopic measurements show important variations between the subantarctic surface waters with low δ¹⁸O–high δ¹³C values and the antarctic surface waters with very low δ¹⁸O–low δ¹³C values. The surface distributions of δ¹³C values follow the major frontal oceanic structures; the vertical distribution shows the progressive upwelling from the subantarctic zone to the antarctic divergence of ¹³C-depleted CO₂ derived from remineralization of organic matter. Along the Antarctic continental shelf, between 2500 and 4000 m, a core of water with δ¹⁸O values close to −0.1‰ is associated with a relative maximum in CFC-12 concentration, although this core is not detected by its temperature and salinity parameters. This water mass, which corresponds to recently formed deep water, may originate from the eastward extension of the Weddell gyre or from bottom waters coming from the East and formed near Prydz Bay.     

The use of PPP's and the profitability rate paradox

Over the past twenty years growth in the use of PPPs for new infrastructures has signalled a significant change which completely redefines the issues of public economics in the field of transport policy. This paper concerns the optimal casting between public sphere and private operators. The analysis is based on relationships linking for each project the subsidy rate, the internal rate of return (IRR) and the additional IRR provided to the operator by subsidies. The need for subsidy appears as an increasing function of this additional IRR. Nevertheless, the gradient of the curve decreases in a marked manner. This concavity has some policy oriented consequences.     

Programming, optimal pricing and partnership contract for infrastructures in PPPs

The development of various forms of public-private partnerships for the financing, building and operating of public infrastructure has not fundamentally altered the economic calculations involved. This chapter examines to what extent it is necessary, however, to change the way that government uses socio-economic and financial evaluations, whether to optimise investment programming or pricing. Ensuring a coherent match between these two types of optimisation can provide a principle for determining the optimal programming price.We begin by showing that when projects are financed by both users (toll revenues) and taxpayers (subsidies), it is socially beneficial to plan these investments on the basis of the net present value (NPV) provided by each unit of public money invested. This NPV/subsidy ratio must obviously be higher than the public-funding scarcity coefficient or else the investment would destroy more wealth than it would produce.One of the ways of improving this ratio is also to optimise the toll level, since increasing it can lower the subsidy but has an adverse impact on the user surplus, it is essential to set the optimal toll.In the case of an approved project considered in isolation, we show that the optimal toll depends upon the public-funding scarcity coefficient. If there is no scarcity, the optimal toll is zero. As public-funding becomes scarcer, the optimal toll draws closer to the toll that optimises revenue.In the case of a programme of several projects subject to budget constraint, we show that the optimal toll no longer depends upon the public-funding scarcity coefficient and that there are several scenarios depending on the relative values of the maximum revenue and the total cost of the project:

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when, whatever the toll, revenue can no longer cover over half of the cost, it is socially beneficial to choose not to levy any toll;

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when there is a toll that covers the total cost, the operator may be left free to set it at the level he sees fit, with the issue of how the profits are to be shared between the franchisee and the franchisor being settled separately;

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when the maximum revenue of the project falls between half and all of the total cost, the value of the toll that maximises the welfare function is lower than the revenue-maximising toll and must therefore be set for the private operator by government.

Thus, the partnership contract must be given a different content in these three cases of optimal pricing.

Preamble

Most of the theoretical studies devoted to optimising public investment programming and infrastructure pricing have, since the work of Jules Dupuit (1844), focused on the salient issues of the transport sector, even though this work was relevant to all sorts of public infrastructure. The analysis presented in this paper deals with transport economics, but in line with this tradition, is also applicable to any field in which public-funding is combined with commercial revenue. For example, the question of determining how the financing of an opera should be shared between taxpayers and opera-goers raises the same type of issues as the optimal combination of tolls and subsidies for financing a motorway project. This report will be focused on these issues. We shall see that certain precautions are called for in investment programming together with some new thinking on pricing principles.     

Turbo小狮王

国产的标致小狮王206装备了1．6升的发动机，如果将其加上一个涡轮增压器（Tudbo）是什么情况呢？     

阿库拉游艇Acura MD-X Concept

亮相于2006年纽约国际车展上的MD-X．是阿库拉为庆祝其品牌创立20周年而推出的一款概念豪华SUV。今年晚些时候,新一代MD-X将以此为模型在北美地区设计和生产。     

性感毒蛇Iroc Sports Car Concept

曾于33年前在日内瓦国际车展上展出,大众紧凑型双门跑车Scirocco强烈吸引了人们的目光。随后,它在市场上的表现同样不俗,第一代车型销售量超过50万辆,在2006年这家欧洲最大的汽车公司重新演绎了Scirocco的精神,这就是最近在柏林登场的Iroc运动概念车。     

A hybrid controller for autonomous vehicles driving on automated highways

This paper addresses the problem of the hybrid control of autonomous vehicles driving on automated highways. Vehicles are autonomous, so they do not communicate with each other nor with the infrastructure. Two problems have to be dealt with: a vehicle driving in a single-lane highway must never collide with its leading vehicle; and a vehicle entering the highway at a designated entry junction must be able to merge from the merging lane to the main lane, again without any collision. To solve these problems, we equip each vehicle with a hybrid controller, consisting of several continuous control laws embedded inside a finite state automaton. The automaton specifies when a given vehicle must enter the highway, merge into the main lane, yield to other vehicles, exit from the highway, and so on. The continuous control laws specify what acceleration the vehicle must have in order to avoid collisions with nearby vehicles. By carefully designing these control laws and the conditions guarding the automaton transitions, we are able to demonstrate three important results. First, we state the initial conditions guaranteeing that a following vehicle never collides with its leading vehicle. Second, we extend this first result to a lane of autonomous vehicles. Third, we prove that if all the vehicles are equipped with our hybrid controller, then no collision can ever occur, and all vehicles either merge successfully or are forced to drop out when they reach the end of their merging lane. Finally, we show the outcome of a highway microsimulation modelled after the Katy Corridor near Houston, Texas: our single-lane highway can accommodate 4000 vehicles per hour with neither drop-outs nor traffic congestion. It is entirely programmed in SHIFT, a hybrid systems simulation language developed at UC Berkeley by the PATH group. This shows that SHIFT is a well suited language for designing safe control laws for autonomous highway systems, among others.