JTG Special Section on Accessibility and Socio-Economic Activities: Methodological and Empirical Aspects (original) (raw)
Related papers
Guest Editorial: New Frontiers in Accessibility Modelling: An Introduction
Networks and Spatial Economics, 2011
There is a well established body of research that deals with how accessibility affects land use planning and spatial interaction. Hansen (1959) is usually cited as the father of this "scientific term". In his seminal work, he defines accessibility as "the potential of opportunities for interaction" (p.73). Since then, the interest of how transport systems and spatial interaction are related has grown exponentially and accessibility analysis has played for more than five decades a central role in the agenda of regional and transport research. The concept of accessibility is open to different areas of study regarding the activities that can be carried out, to multiple transport systems and to different individuals or groups, so it is not surprising that in the literature we can find many different definitions (Geurs and van Wee 2004; Bruinsma and Rietveld 1998; Reggiani 1998; Vickerman 1995; and Morris et al. 1979). Handy and Niemeier (1997) showed that different types of accessibility measures exist according to particular criteria, and it is difficult to suggest the best approach to measure accessibility because different situations and purposes demand different approaches. This comment is quite pertinent at the light of the articles included in our special issue. We will see that four of them analyze accessibility in commuting and the authors use different methods, demarcation areas and opportunities are in some cases aggregated at the level of areas or individuals. In the last decade with the continuing development and deployment of geographic information systems (GIS) and other geospatial technologies that have greatly enhanced the ability to collect and analyse data relevant to accessibility analysis, researchers, in some cases, have changed from place-based measures of accessibility
An overview of accessibility measures
This paper presents a review of accessibility measures in transportation studies by addressing its conceptual framework, data requirements, and applications. Depending on the theoretical basis, the accessibility measures are classified in infrastructure, location, gravity, space-time and utility-based measure. A system approach is applied to identify the relations among the interacting variables: land-use, transportation, temporal and individual ones. The criteria, including theoretical basis, interpretability, and data requirements are used to evaluate these measures. Recent progress in accessibility studies point towards the inclusion of more individual's spatial-temporal accessibility measure (using the space-time prism concept) but the data requirements, and interpretability of this measure remain as a problem. Furthermore, most of the measures fail for not considering the competition for opportunities (e.g. jobs on the employment market), and it seems to be the main issue for the development of more realistic accessibility measures.
Why accessibility measurement is not merely an option, but an absolute necessity
Many authors and advocates have argued over the past decades that the traditional mobility-centered approach to transportation planning needs to be replaced with an accessibility-centered approach. But while the interest in accessibility is on the rise, in practice transportation (and land use) systems still tend to be evaluated using traditional mobility-centered performance indicators, like the level-of-service criterion or travel time savings. The aim of this chapter is to provide an argument that the assessment of accessibility is not merely an option, but an absolute necessity. The paper starts by distinguishing three, partly overlapping, goals of transportation planning: activity participation, economic development, and environmental quality. Subsequently, the interrelationship between accessibility measurement, accessibility indicators, and each of these goals is explored. That exploration leads to the conclusion that the measurement of accessibility is not of intrinsic value if policy makers seek to promote economic development or environmental quality. While accessibility is related to both goals, other performance indicators may be more suitable if decision-makers are interested in advancing either goal. The analysis results in a radically different, and perhaps counter-intuitive, conclusion regarding the goal of activity participation: if decision-makers are interested in the goal of activity participation, it would be fundamentally wrong to measure a transportation (and land use) system’s contribution to actual activity participation. The goal of activity participation requires measurement of accessibility, as only by doing so it is possible to account for persons’ constitutive interests in the range of states they can achieve. Hence, the conclusion that accessibility measurement is not merely an option but an absolute necessity, if decision-makers want to take the constitutive interests of persons seriously in the design of transportation systems.
Measuring accessibility: a review and proposal
Environment and Planning A 11(3) (1979), 299 – 312.
An attempt is made to clarify some of the confusion about the notion of accessibility by examining the limitations, strengths, and conceptual bases of distance, topological, gravity, and cumulative-opportunity measures of accessibility. In their aggregate and disaggregate states the measures are practical, enabling measurement into the future and measurement with a minimum of data, but the assumptions that all nodes are potential destinations and that all origins are known severely restrict the meaning and uses of the measures. Time - space measures of accessibility do not make these assumptions although they are data hungry, retrospective, and share with the other measures the narrow conception of accessibility as a property of the built environment. It is proposed that accessibility be thought of as a vacancy in an activity routine and that it be measured in terms of the disruption involved in creating it.
Accessibility Long Term Perspectives
Journal of Transport and Land Use, 2008
Improved accessibility and its correlate lower generalized cost of contact, travel and transport have been sought by dynamic human societies for their economic and social bene ts throughout recorded history. e paper will re ect about this process at a number of different spatial and temporal scales based on a conceptual model. Looking back at European history, it will trace the interaction between Christaller's logic of local market areas and the idea of (low contact cost) network cities. Focusing on Switzerland since 1950 it will show how network investment changed the relative distribution of population and employment and how this interacted with changes in the preferences of the travelers. Using a recent snapshot of how a substantial sample of Swiss maintain their social networks over often very large areas, it will try to answer the question of what will happen in the future, if the current trend of ever lower costs of contact persists.
Urban accessibility: the paradox, the paradigms and the measures. A scientific review
Tema. Journal of Land Use, Mobility and Environment, 2020
TeMA is the Journal of Land Use, Mobility and Environment and offers papers with a unified approach to planning, mobility and environmental sustainability. With ANVUR resolution of April 2020, TeMA journal and the articles published from 2016 are included in the A category of scientific journals. From 2015, the articles published on TeMA are included in the Core Collection of Web of Science. It is included in Sparc Europe Seal of Open Access Journals, and the Directory of Open Access Journals. The The Times They Are a-Changin' and cities have to face challenges which may not be further postponed. The three issues of the 13th volume will collect articles concerning the challenges that cities are going to face in the immediate future, providing readings and interpretations of these phenomena and, mostly, methods, tools, technics and innovative practices (climate proof cities, zero consumption cities, car free cities) oriented to gain and keep a new equilibrium between cities and new external agents.
Accessibility: a useful analytical and empirical tool in spatial economics – experiences from Sweden
2013
Accessibility has for many years been a widely used tool in transportation research. Many definitions have been suggested and researchers have constructed numerous mathematical formulations to measure its value to be able to evaluate the relationships between the nature of the transport systems and the patterns of land use. Such correlations have been used especially in assessing existing transport systems and forecasting their performance to provide decision-makers with ideas about the need for investments in the transport systems. However, accessibility measures can be regarded as the spatial counterparts of discounting. The measures represent the spatial distribution of economic agents and their activities in a simple way that imposes a very clear structure upon the relationship between these agents and their activities and their environment. Various frictional effects arising from geographical distance between economic agents determine their interaction options, i.e., their opti...
Accessibility measures from an equity perspective
In recent years, there has been an increasing interest in accessibility measures as a performance indicator of transport systems and, sometimes, of integrated land-use and transport interventions, in both academia and practice. This development is more than the replacement of one performance indicator, typically the level-of-service indicator as used in much of mainstream transport planning, by another. The level-of-service indicator was applied to a transport network or parts thereof. In contrast, accessibility measures inevitably apply to the users of the transport system. They generate insight into the level of accessibility for specific users groups, whether by geographical location, mode availability, income, race, or travel motive (work, leisure, business, freight). As a consequence, the shift towards accessibility measures inevitably, and much more overt than in the case of mainstream transportation planning, directs the attention to the distributive question in transport: who reaps the accessibility benefits from investments in the transport system (Talen and Anselin, 1998)? As the distributive question is highly political, so is the use of accessibility measures. Different measures may result in different distributive patterns and hence point to different policy responses. This does not imply, however, that the choice of an accessibility measure is merely a political issue. Rather, we argue that the choice for a certain accessibility measure should be based on a clear understanding of the responsibility of both government and transport system user for the level of accessibility of that user.
2014
One of the core objectives of urban planning practice is to provide spatial equity in terms of opportunities and use of public space and facilities. Accessibility is the element that serves this purpose as a concept linking the reciprocal relationship between transport and land use, thus shaping individual potential mobility to reach the desired destinations. Accessibility concepts are increasingly acknowledged as fundamental to understand the functioning of cities and urban regions. Indeed, by introducing them in planning practice, better solutions can be achieved in terms of spatial equity. The COST Action TU1002 "Accessibility instruments for planning practice" was specifically designed to address the gap between scientific research in measuring and modelling accessibility, and the current use of indicators of accessibility in urban planning practice. This paper shows the full process of introducing an easily understandable measure of accessibility to planning practitio...