Who doesn’t mind waiting? Examining the relationships between waiting attitudes and person- and travel-related attributes

Transportation - Waiting, whether for services, for someone, or for something, is an inescapable part of life. This paper addresses a gap in the waiting time literature by examining previously...     

Thermal buckling and post-buckling behaviour of continuous welded rail track

Because thermal expansions are constrained within continuous welded rail track, the track can buckle, and does so mainly in the horizontal plane. In this paper, a parametric finite element model of railway track is presented, and its sensitivity to the variations of the main parameters that characterise the scenario has been investigated and discussed. Comparison with existing literature shows good agreement. It is found that curved tracks suffer from thermal buckling more than tangent tracks do. To simulate a track misalignment defect, a new methodology has been utilised that does not introduce, as is usual, geometrical discontinuities near the same defect, because it takes into account – in a natural way – the bending stiffness of the whole railway track in the horizontal plane. To contribute to a better understanding of the safe utilisation of raw experimental data obtained from in situ tests, a deep analysis of the effects on the thermal track buckling response produced by each parameter characterising the sleeper–ballast lateral resistance curve is presented and discussed. It is found that for current ballasted railway tracks, the minimum buckling temperature depends only on the limit lateral resistance, whereas a high value of the initial stiffness can lead to overestimation of the maximum buckling temperature, also taking into account the ‘natural’ decrease in the maximum buckling temperature due to an increase in the railway-traffic-induced defect amplitude.     

Dealing with uncertainty and volatility in the port industry network: social and instrumental antecedents of “clique” survival

The recent proliferation of inter-firm collaborative linkages within the container port industry is progressively shaping a complex architecture of voluntary ties among terminal operators, i.e. an inter-organizational network. Within the overall industry network, some stable groups of densely interconnected firms emerge suggesting the existence of “cliques” where firms repeatedly cooperate with each other and develop strong and durable ties. The growing pressure exerted by economic uncertainty and market volatility on clique stability stimulates a fruitful academic debate on clique survival and its determinants. The present contribution investigates social and instrumental antecedents of clique survival, focusing on equity joint ventures engaged by terminal operators in a 10-year time frame (2002–2011). For this purpose, this study introduces a longitudinal network analysis of inter-firm relationships. Research hypotheses are tested performing binomial logistic regression analysis. In line with network theory assumptions, the outcomes corroborate the explanatory role of a number of social (i.e., cultural similarity and organizational mismatch) and instrumental (i.e., the presence of core firms within the clique and clique equality) antecedents in the survival of cliques. The results, indeed, bring valuable implications for both academics and practitioners.     

Transport and equity in Latin America: a critical review of socially oriented accessibility assessments*

ABSTRACT

A growing concern for mobility-related social inclusion and equity is evident from both academic research and planning best practices. Scholarly research promotes accessibility as the main aim of transport planning, assuming it as the evaluative approach that better conveys how mobility contributes to individuals' well-being and participation in social life. Accessibility can be crucial to address the socio-spatial inequalities that characterise manifold settings across the world. Amongst them, Latin American countries have been keen in tackling such imbalances through mobility-related interventions, as the renowned cases of Curitiba, Medellin and Bogotá show. The widespread interest in mobility as both a cause and effect of social disparities has generated an increasing stream of work that examines Latin American settings through the lenses of accessibility. This paper aims at critically reviewing the growing scholarly works that, providing accessibility-based evaluations, has examined issues of transport and equity in Latin America. Proposing a novel conceptual framework that considers the underlying ethical stance, components of accessibility and implications for planning and policy, this work examines what approaches, features and indicators are present in the current literature, as well as what settings have been taken into consideration by scholarly research. Moreover, the review has an explicit operational interest, to define what indicators are relevant or missing to assess accessibility in the light of social concerns, as well as to consider the current and potential implications that such research findings have on transport planning and policy. The review highlights how a growing but still limited body of work has examined transport and equity in Latin America, suggesting academic, technical and operational avenues to enhance theoretical and practical approaches to the issue.