Abstract

International audience; En este libro se presenta una reflexión sobre los riesgos a los cuales está expuesto el Distrito Metropolitano de Quito –DMQ– considerando la cuestión de la movilidad cotidiana de las personas y la cuestión de la accesibilidad. Este análisis se funda en un método elaborado en el marco del programa “Sistema de información y riesgos en el DMQ” llevado a cabo por la Dirección Metropolitana de Territorio y Vivienda del Municipio de Quito y el Institut de Recherche pour le Développement (IRD, ex ORSTOM). Para prevenir eficazmente los riesgos a los cuales está expuesta la capital ecuatoriana por problemas de movilidad habituales o excepcionales, es imprescindible enfocar el análisis en las obras viales claves y los equipamientos de transporte esenciales. En efecto, la pérdida de su operatividad podría dificultar gravemente las comunicaciones y reducir fuertemente la accesibilidad de algunos sectores lo que causaría perjuicios muy severos al territorio metropolitano. La situación es tanto más crítica cuanto que las obras claves son vulnerables y tanto más problemática cuanto que los sectores en cuestión cuentan con funciones urbanas estratégicas (grandes equipamientos de la logística urbana, grandes centros hospitalarios,...). En primer lugar se estudia los flujos y movimientos de personas y el sistema de transporte vigente. Se identifica y localiza en la segunda parte las infraestructuras claves de la movilidad. En una tercera fase se analiza los factores de vulnerabilidad de estas infraestructuras claves, vulnerabilidad que las predisponen a fallos o daños. Por último se aborda los riesgos a los cuales está expuesto el Distrito dada la reducción de la accesibilidad de los diferentes espacios metropolitanos que puede resultar del cierre de las vías claves. En una perspectiva de planificación urbana preventiva, el libro proporciona una base de reflexión para los gestores, pistas para la reducción de la vulnerabilidad y medidas encaminadas a orientar la gestión de crisis. Si bien se dirige a los encargados del manejo del transporte o riesgos, este libro está destinado a los planificadores urbanos y de manera general a todo público interesado en comprender el funcionamiento de la movilidad de las personas y la vulnerabilidad de la capital ecuatoriana.; Ce livre présente une réflexion sur les risques encourus par le District Métropolitain de Quito –DMQ– en considérant la question de la mobilité quotidienne des personnes et la question de l'accessibilité. Cette analyse s'appuie sur une méthode mise au point dans le cadre du programme « Système d'information et risques dans le DMQ » mené par la Direction Métropolitaine du Territoire et du Logement de la Municipalité de Quito et l'Institut de Recherche pour le Développement (IRD). Pour prévenir de façon efficace les risques auxquels est exposée la capitale équatorienne compte tenu des problèmes de mobilité habituels ou exceptionnels, il est indispensable de cibler l'analyse sur les infrastructures routières enjeux et sur les équipements de transport enjeux. En effet, la perte de leur opérationnalité pourrait compromettre sérieusement les communications et réduire fortement l'accessibilité de certains secteurs, situation qui handicaperait gravement le territoire métropolitain. La situation est d'autant plus critique que les enjeux sont vulnérables et d'autant plus problématique que les secteurs en question rassemblent des fonctions urbaines stratégiques (grands équipements de la logistique urbaine, grands centres hospitaliers...). En premier lieu, sont étudiés les flux et de personnes et le système de transport actuel. En second lieu, sont identifiées et localisées les infrastructures enjeux de la mobilité. En troisième lieu, les vulnérabilités déplacements enjeux, les prédisposant aux défaillances ou à l'endommagement, sont analysées. Enfin sont évalués les risques encourus par le District compte tenu de la réduction de l'accessibilité des différents espaces métropolitains pouvant découler de la fermeture des routes enjeux. Dans une perspective de planification urbaine préventive, le livre propose une base de réflexion utile aux gestionnaires, fournit des pistes pour la réduction des vulnérabilités et apporte des orientations pour la préparation aux crises. S'il s'adresse aux responsables de la gestion des transports ou des risques, ce livre est aussi destiné aux planificateurs urbains et de manière générale à quiconque désire comprendre le fonctionnement de la mobilité des personnes et la vulnérabilité de la capitale équatorienne. Document type: Book

Abstract

This paper discusses possible contributions of psychologists to sustainable transportation. It is argued that in order to reach sustainable transportation, among others, behaviour changes of individual car users are needed. As transport policies will be more effective if they target important antecedents of travel behaviour, first, factors influencing such behaviour are discussed. It is argued that car use is very attractive and sometimes even necessary for many different reasons. This implies that a combination of policies is called for, each targeting different factors that support car use and hinder the use of more sustainable modes of transport. Next, the paper elaborates on policy strategies that may be employed to achieve sustainable transportation by changing car use. Increasing the attractiveness of sustainable transport modes by means of pull measures seems not sufficient to reduce the level of car use. Besides, car use should be made less attractive by means of push measures to force drivers to reconsider their travel behaviour. The acceptability of such policies may be increased by clearly communicating the aim of these policies, and the expected positive consequences (e.g., less congestion, improved environmental quality). Moreover, possible negative effects for individual freedom may be compensated by implementing additional policies aimed at facilitating the use of sustainable transport modes. Document type: Part of book or chapter of book

Abstract

The spatial and temporal distribution of built space supply plays an important role in shaping urban form and thus the general travel pattern in an urban area. Within an integrated framework, we are interested in modeling the decisions of a builder in terms of when, where, what type, and how much built-space to build. We present a multidimensional discrete-continuous model formulation for the built space supply decisions that are based on expected profit maximization. The framework is applied to estimate a model for supply of new office space in the Greater Toronto Area (GTA) for the duration of 1986 to 2006. To our knowledge, this work is the first that models the where, when, how much, and what type of office space to supply in a single econometric framework at a fairly disaggregate spatial zoning system. The results indicate a risk taker behaviour on the builders part, while market conditions and supply of resources (labour, construction cost etc.) are also found to be important factors in decision making.

Abstract

Consider the choices available to a shopper driving to a city and trying to park downtown. One option, typical to many cities, is to follow the signposts to an off-street parking facility, which is often privately operated. Another option is to search for an on-street spot. If this proves unsuccessful, it is always possible to return to the off-street facility. We formalise such a setting and examine optimal on-street parking policy in the presence of an off-street market. Not surprisingly, the amount of socially-wasteful searching behaviour is shown to depend on the prices of both the off- and on-street market. If the off-street market is run competitively, optimal on-street policy reduces to a simple and attractive rule: set the on-street price equal to the resource cost of off-street parking supply. Other pricing rules result in either excessive searching behaviour or excessive off-street investment costs. Time restrictions - a common alternative to on-street fees - are also shown to be inefficient. In practice, however, off-street markets are unlikely to be competitive. We examine the case of a single off-street supplier playing as a Stackelberg follower to the government regulated on-street market. Based on a numerical example (calibrated to London), optimal on-street policy is shown to either involve setting a relatively high on-street price, such that the monopolist is induced to undercut and gain the entire parking demand, or setting a relatively low price, while the monopolist maximises profit on the residual demand curve. Which strategy is optimal is shown to be parameter dependent.

Abstract

Tokyo’s railway station areas are models of transit-oriented design. To differentiate them from transit-oriented developments (TOD), the term rail integrated community (RIC) has been created to describe these high density, safe, mixed-use, pedestrian-friendly developments around railway stations that act as community hubs, served by frequent, all-day, rail rapid transit and are accessed primarily on foot, by bicycle, or by public transit. Japanese private railways have been instrumental in creating these RICs. Though they receive little financial support from the government, private railways in Japan achieve profitability by diversifying into real estate, retail, and numerous other businesses. Tokyu Corporation is used as the case study to exemplify how government policy and socioeconomic context contributed to the successful private railway model. Ten indicators, such as ridership, population density and mode share are used to analyze two stations created by Tokyu to demonstrate how this model is manifested in Tokyu’s rail integrated communities.

Abstract

The increased availability of detailed trajectory data sets from naturalistic, observational, and simulation-based studies, is a key source for potential improvements in the development of detailed safety models that explicitly account for vehicle conflict interactions and various driving maneuvers. Despite the well-recognized research findings on both crash frequency estimation and traffic conflict analysis carried out over the last decades, only recently researchers have started to study and model the link between the two. This link is typically made by statistical association between aggregated conflicts and crashes, which still relies on crash data and ignores heterogeneity in the estimation procedure. More recently, an extreme value (EV) approach has been used to link the probability of a crash occurrence to the frequency of conflicts estimated from observed variability of crash proximity, using a probabilistic framework and without using crash records. In this study the Generalized Extreme Value distribution used in the block maxima (BM) approach and the Generalized Pareto Distribution used in the peak over threshold approach (POT), are tested and compared for the estimation of head-on collisions in passing maneuvers. The minimum time-to-collision with the opposite vehicle is used in both EV methods. Detailed trajectory data of the passing, passed and opposite vehicles from a fixed-based driving simulator experiment was used in this study. One hundred experienced drivers from different demographic strata participated in this experiment on a voluntary basis. Several two-lane rural highway layouts and traffic conditions were considered in the design of the driving simulator scenarios. Raw data was collected at a resolution of 0.1 s and included the longitudinal and lateral positions, speeds and accelerations of all vehicles in the scenario. From this raw data, both methods were tested for stationary and non-stationary models. The latter allowed not-only for a better modeling performance in estimating the number of expected crashes, but also for a quantified analysis of the detailed driving choices affecting the head-on crash probability during passing maneuvers. The estimation results showed that the BM approach yielded more stable results compared to the POT approach, but the latter was able to produce crash rate estimates more consistently sensitive to the covariates of interest. Finally, the estimated distributions were validated using a second set of data extracted from an additional driving simulator experiment. The results indicate that this is a promising approach for safety evaluation. On-going work of the authors will attempt to generalize this method to other safety measures related to passing maneuvers, test it for the detailed analysis of the effect of demographic factors on passing maneuvers' crash probability and for its usefulness in a traffic simulation environment.

Abstract

In much of Switzerland, public transport offers high levels of accessibility to workplaces and other places that make season tickets legitimate substitutes for a car. These similar patterns of accessibility provided by both modes result in high levels of correlation between the accessibility measures of both modes. This correlation almost always precludes a travel behavior analysis with several accessibility measures and cannot provide any insights into the effects of the differences in accessibility levels by both modes. We propose a principal component analysis of the accessibility measures to extract as much information as possible. We interpret the principal components obtained as: general accessibility, comparatively better accessibility by public transport and comparatively better job accessibility. The new accessibility variables are used in a model of car and season ticket ownership and the number of car, public transport and non-motorized trips using data from the 2010 Swiss transportation microcensus. These outcomes are jointly estimated with a probit-based model for mixed types of outcomes because we anticipated simultaneous choices and that choices are dependent on each other. We found that greater levels of general accessibility, comparatively better accessibility by public transport and comparatively better job accessibility increased the probability of season ticket ownership, while the probability of car ownership decreased. We realize that ownership and use must be jointly modeled to consistently estimate the structural effects of mobility tool ownership on use. ISSN:1938-7849

Abstract

Congestion and traffic-related pollution are typically the largest contributors to air pollution in cities. Rapid urbanization in developing countries has caused large-scale proliferation in motor vehicle use making cities increasingly congested and, subsequently, polluted. There is a growing awareness that the air quality status quo in East African cities is unacceptable. This paper uses the case of Nairobi, Kenya to discuss current traffic pollution challenges and how they may be addressed. The paper begins with an overview of urbanization and pollution effects. It goes on to look at the specific case of Nairobi as it searches for solutions to the negative impacts of pollution through a lens which sees resolution of congestion effects as key to amelioration of traffic-related air pollution. It suggests that a combination of infrastructure, policy, regulatory and softer measures may provide the most effective way to address traffic congestion and, thus, traffic pollution. In addition, the paper highlights the need for further research into the lived experience of negotiating daily life in Nairobi, as well as further exploration of the social, economic and environmental feasibility of potential solutions for the city. While Nairobi is used as the case study city, the lessons learned are generalized for cities in the East African region, which often share similar traits of congestion and traffic related pollution.

Abstract

This paper studies some of the properties and fundamentals of static models of road traffic congestion that have triggered much debate in the literature. The first part of the paper focuses in particular on the difficulties arising with the backward-bending cost curve in the context of 'continuous congestion'. Therelevance of the backward-bending segment of the cost curve for the static analysis of congestion is questioned by demonstrating that 'equilibria' on this segment produce upwards shifts of the cost curve itself, and can therefore not be of a stationary nature. Next, the implications for static models of 'peakcongestion' are considered. In doing so, the paper addresses the implicit assumptions, particularly on the nature of scheduling costs, that are necessary to render static models of peak congestion internally consistent. The paper ends with a brief discussion of the implications for dynamic models of peakcongestion.

Abstract

There is a growing body of international evidence available that shows highway construction fails to solve issues of congestion and improvements to the local economy. There is also evidence that due to changes of land use and expectations of being able to travel from the land opened for development that traffic is induced to the highway network. Alternative methods of managing travel demand; such has Voluntary Travel Behaviour Change (VTBC) initiatives have been delivered internationally. A significant VTBC scheme, called the Local Sustainable Transport Fund (LSTF), was delivered in the United Kingdom between 2011 and 2015. This paper focuses on the people who delivered these initiatives, rather than the individuals required to change their behaviour. This is to understand how transport planners’ views influence the type of VTBC initiatives that were delivered. The study included a survey of 69 bid managers for LSTF projects and interviews with 17 council officers. The survey found that 80% transport planning officers understood the concept of induced traffic compared to just 10% of the wider population. It was also evident that the sample group was a homogenous group, where their views on issues such as climate change, congestion and the factors that influence how we travel were remarkably similar. The findings show that despite the evidence that highway construction does not provide a solution to travel demand, the decisions about which schemes are funded remain with non-transport experts, such as government ministers and local politicians, and this invariably leads to highway ‘solutions’ being chosen which limit the potential success of any VTBC initiative to create long-term change to travel behaviour. Document type: Article