Using demand elasticities from disaggregate mode choice models

Three of the most highly regarded disaggregate mode split models incorporate very different estimates of the responsiveness, or elasticity, of mode choice to changes in auto travel times and costs. These differences appear to be due in part to the varying specifications used by the model, and particularly whether certain variables (such as a dummy variable for CBD destinations or automobile ownership) are included in addition to the more traditional variables (such as travel time, cost, and household income). More research is needed on the implications of the theory of traveler choices for model specification and the effect of alternative, but theoretically justifiable, specifications on elasticity estimates. Until this research reduces our uncertainty about the elasticity of demand, analysts evaluating transportation policies should assess the sensitivity of their results to the range of plausible elasticities or models.     

高速铁路对都市区一体化的影响 ——以伦敦、马德里和巴黎为例

高速铁路建设的最初目的是连接相距400~600 km的都市区.但是近年,都市地区的郊区及城市出现了一些边缘位置的高铁车站,距都市中心的距离约100 km.重点研究位于马德里(瓜达拉哈拉、塞戈维亚和托莱多)、伦敦(斯特拉特福德、艾贝斯费特和阿什福德)和巴黎(鲁瓦西—戴高乐、马恩河谷—谢西和马西)附近的9座外围高铁车站,分析它们对都市区及当地的影响,并提取对加利福尼亚州高速铁路项目可借鉴之处.     

Technical characteristics and efficiency of urban bus companies: The case of Spain

The aim of the present study is twofold. First, to provide new information concerning the technical characteristics of urban bus companies on the basis of a sample of medium and large-size cities in Spain. Second, to analyze the degree of efficiency of those companies and to quantify the reasons for this efficiency. The results should be useful in evaluating possible changes in public policies relating to urban transport, specifically changes in the way the market is organized and in pricing.The analysis is carried out by estimating a cost function. The sample is made up of a panel data set consisting of observations of nine Spanish companies that operated during the period 1983–1995. The specified functional form is translogarithmic. The output unit of measure adopted is bus*kms run. The cost function includes the network length for each company, thus permitting evidence concerning economies of density and economies of scale.The use of panel data allows us to estimate the cost function, taking into account that each company is affected by the specific characteristics of each individual city, the different features of the network in question and by different levels of efficiency. The economies of scale have been calculated, taking into account that the features of the network and of the city – represented by their specific individual effect – will vary with the company's level of output.Finally, an analysis is made of the relative productive efficiency of the companies, as well as of the variables likely to influence that efficiency.     

Managing a smart bicycle system when demand outstrips supply: the case of the university community in Seville

Of the many public initiatives used to promote the use of bicycles in the urban environment, the one that has achieved the most spectacular results in a short period of time is the public bicycle hire system. The experience of Seville is one of the most successful internationally, where 6.6 % of mechanised trips were being made by bicycle within 30 months. This paper analyses this experience in the university community, which represents one-third of system users. We conclude that the people who are most satisfied with the system are those who use it for leisure and recreation activities, non-residents of the city, more environmentally aware people and those who have no alternative mode of transportation. Their satisfaction is also closely linked to their appreciation of the bicycles’ level of comfort, the ease with which users can hire bicycles and return them and the small amount of paperwork involved required to sign up for the system. However, user appreciation has fallen over time because the system’s rapid success has caused it to become overloaded. This experience therefore provides one main lesson: the system’s success can result in eventual difficulties.     

Extending the Scope of Highway Planning: Accessibility,Negative Externalities and the Residential Context

The objectives of this review-based paper were twofold. Firstly, we aimed to explore the need and possibilities for broadening the scope of highway planning by taking account of the residential context, including residential satisfaction. Satisfaction appears to be an interesting, and in our opinion, valuable mediating planning concept between road infrastructure planning and the accompanying external effects on the one hand and household coping strategies on the other. Households living near highway infrastructure are influenced by both positive (i.e. accessibility gains) and negative road-related factors (e.g. noise nuisance and air pollution). Changes in these factors may trigger people to accept the new situation, adjust preferences, try to influence plans and/or even relocate. The second aim was to gain a greater understanding of the influence of both accessibility characteristics and negative externalities on the residential context of households. With respect to context, we make a distinction between residential satisfaction, housing prices and residential relocation. We see changes in residential satisfaction as a potential early predictor of opposition to plans, not only from active opposers but also from the more ‘silent majority’, and as a predictor of housing price changes and residential migration. Insights into residential satisfaction around highways may help transportation planners to relieve locational stress and may also prevent protests and relocations. Our literature review indicated that households prefer to live close to highways to benefit from high regional accessibility, but do not want to contend with the nuisances. This is also reflected in property values. However, the literature appears to put more emphasis on studying the impact of (regional) accessibility and externalities on location behaviour than on residential satisfaction. Because of the added value that the concept of residential satisfaction may provide in road planning, and the limited scientific insights, it is important to gain greater insight into how residential satisfaction is influenced by negative and positive externalities and into how residential satisfaction changes over time—from the stage when new road projects are discussed through to concrete planning, realization and the period after completion. Moreover, it would be worthwhile to gain a deeper understanding of the extent to which house prices, location behaviour and residential satisfaction near highways interrelate.