The causal relationship between GDP and domestic air passenger traffic in Brazil

Abstract

This paper examines the causal relationship between economic growth and domestic air passenger transport in Brazil, using Granger's causality test. Total domestic passenger-kilometres are used as a proxy for air transport demand and gross domestic product as a proxy for economic growth. The test spans the period from 1966 to 2006. The results lead to the acceptance of the hypothesis that there is a unidirectional Granger causal relationship from economic growth to domestic air transport demand in Brazil, having a high elasticity in the short term.     

Incorporation of customer satisfaction in public transport contracts – A preliminary analysis

The design of public transport contracts provides an opportunity to define service quality standards to which an operator can be held accountable. While the specification of service quality standards is a common practice, the relationships between the specifications and customer satisfaction are often methodologically unclear. Based on a South African case study, the paper uses data collected from a group of passengers who have personal cars but choose to use public transport, and a control group of passengers who only use their cars, in the same corridor as the user group, to estimate a service quality conjoint model. The model is used to evaluate the effect of different public transport service packages, defined in terms of different combinations of service attributes, on passenger satisfaction. The paper confirms the need to classify service attributes in terms of their relative impact on passenger satisfaction, at the service design stages, where performance in respect of some attributes has a disproportionate impact on satisfaction, especially where public transport is competing directly with private transport. Practical applications and limitations of the methodology are also discussed.     

基于非线性模型预测控制的车辆纵向队列协调控制

本文中针对基于分层控制结构的车辆队列上、下层控制缺少联系的问题,提出了车辆队列跟驰与个体车辆动力学稳定性协调控制的思路,其基本思想是在保证队列中个体车辆安全稳定行驶的同时,尽可能实现队列跟驰控制的目标。基于非线性模型预测控制(nonlinear model predictive control,NMPC)方法设计了车辆队列协调控制方案,设计了包括跟驰间距误差、跟驰速度误差以及车速与车轮圆周速度差3个子目标的优化目标函数,将队列跟驰与车辆动力学稳定性的协调控制转化为约束优化控制问题;基于序列二次规划(sequential quadratic programming,SQP)方法进行求解,得到车辆前、后轴的制动/驱动力矩来实现上层决策输出的期望跟驰加速度。基于由3车辆组成的非线性队列模型对控制方案进行了仿真分析,结果表明,所提出的基于NMPC的车辆队列协调控制策略可以在大范围操纵工况下,在保证车辆安全稳定行驶的基础上实现队列的跟驰控制。     

Non‐physical barriers to traffic flow and the PTA programme of action: problems and prospects

A lot of resources have .been committed to the provision of transport infrastructure in Eastern and Southern Africa. Some of these resources have been borrowed from outside and have to be repaid. Hence the need to maximize their use. However, this is being minimized by non‐infrastructural bottlenecks to traffic flow. These range from macro‐economic constraints with implications for passenger (bus) transport such as the non‐availability or acute shortage of foreign exchange to slow, cumbersome documentation procedures particularly for cross‐border traffic.

The Preferential Trade Area (PTA) for Eastern and Southern Africa is geared to the reduction and eventual elimination of actual and potential non‐physical barriers to traffic flow, for which it has instituted a number of schemes. After introductory remarks on the sub‐regional economy, its transport sector and avenues for sub‐regional cooperation and the implementation of these schemes is assessed and other non‐physical barriers yet to be addressed by the PTA are examined before conclusions are drawn.     

Does competitive tendering improve customer satisfaction with public transport? A case study for the Netherlands

During 10 years experience with competitive tendering of regional and local public transport in the Netherlands, national average trip satisfaction of passengers increased from 6.84 to 7.25 (+0.41). This is a remarkable improvement, but a closer look at the data reveals that also in regions without competitive tendering the improvement in satisfaction was substantial. The difference in the improvement for regions with and without tendering is only +0.06. Tendering led in the majority of concession areas to an improvement of average trip satisfaction, but in some 40% of the cases a deterioration was observed. A change of operator in general has a negative impact on satisfaction. We also find that the effect on satisfaction of early tendering is larger than of later tendering. This may well be the consequence of a shift in emphasis of authorities and operators from quality improvement to efficiency improvements. The model building and analysis is based on the comparison per year-pair of regions tendered versus regions non-tendered (in that specific year-pair). So we compare the effects on satisfaction of tendered regions relative to non-tendered regions.An analysis concerning the weighted satisfaction judgments of 15 underlying service attributes revealed that ‘service frequency, on-time performance, travel speed, and vehicle tidiness’ contribute the most to the effect on satisfaction in the tendered regions. We found that new vehicles impact highly on satisfaction with travel speed and vehicle tidiness. The emphasis in the tenders with increasing service frequency, led to an increase in satisfaction but, may have a deteriorating effect on (the satisfaction with) on-time performance.     

Public transport in towns - Inevitably on the decline?

Bus transport in Linköping, a town of 140?000 people, was strongly on the increase up to the beginning of the 1980s, when a negative trend-break occurred. A demand model is developed which explains both the ongoing decline and the preceding increase. Based on this model, it is examined whether a change of the current bus transport policy towards an optimal pricing and investment policy from a social point of view could evoke a new and positive trend-break. Taking current trends in the exogenous factors into account it would. However, this could depend on a possible revival of bicycling in towns.     

在福建湄洲湾建设煤炭储运基地势在必行

湄洲湾具有丰富的深水岸线资源,具备建设煤炭储运基地的优良条件。文章阐述在莆田湄洲湾建设煤炭储运基地的重要意义和建设的必要性及可行性。     

Coping with uncertainty: an expedition into the field of new transport technology

Many decisions taken by mankind are rational only to a limited extent. This holds for individual travel behaviour, but also for long-range strategic decisions on transport systems or transport technology. In any decision problem, coping with uncertainty is the most critical element. The introduction of new transport technology is surrounded by uncertainty. For example, there is uncertainty about the pace and extent of adoption of new technology and there is uncertainty about the impact of new technology in terms of increased sustainability or increased efficiency. This article maps uncertainty surrounding new transport technology and identifies ways in which to deal with uncertainty in policy making. The findings will be illustrated with electric vehicles, particularly with two specific strategies to deal with uncertainty: interactive technology watching and experimentation in a market niche. The paper concludes with a discussion of success factors that influence the outcomes of such strategies.     

智能交通系统的现状及发展

论述了智能交通系统的组成及国内外智能交通系统发展状况,对我国智能交通系统的环境、任务现状、发展进行了分析并提出了建议。智能交通系统作为运用现代信息技术将交通四要素“人-车-路-环境”有机结合在一起的系统工程,将从根本上解决困扰现代交通的安全、通畅、节能和环保问题。     

我国动车组维修管理方式探讨

分析我国首条客运提速线——广深线所用瑞典X2000和国产“蓝箭”2种动车组的运用维制青况,从发挥动车组运输效率、方便维护的角度,对我国电动车组的研制与检修管理提出了建议。