Accessibility evaluation of land-use and transport strategies: review and research directions (original) (raw)
Related papers
2019
The Lack of Implementation of Accessibility Instruments The development of Planning Support Systems (PSS) is a well-established practice in academic contexts and consultancy, with numerous examples ranging from out of the shelf, ready to use, products or software, to more conceptual prototypes or frameworks. The field of land use and transport planning, in particular, has been no exception, generating a significant number of PSS in recent years. If anything, the need for PSS has been largely advocated in this research field. Among these, accessibility-based instruments have been considered to have a strong planning support potential in, for instance, bridging the communication gap between land use and transport planners by making the overall goal of the land use and transport system explicit (it is impossible to talk of accessibility without also referring to both land use and transport systems). Despite this focus on planning support, many of the PSS have not been applied in practice. In particular, accessibility-based PSS provide a paradigmatic example of this lack of implementation, regardless of the believed potential for the integration of land use and transport planning. In fact, of the accessibility instruments reviewed in the COST Action TU1002, less than half had been implemented as part of the urban/transport planning process, and even when implemented, it often was a one-off exercise (Hull et al., 2012; Papa et al., 2016). This research project, reported on in this book, sets out to contribute to bridging this implementation gap by exploring why accessibility instruments are not used in practice and what can be done to overcome this lack of implementation. First of all, it is important to point out that the lack of implementation of accessibility instruments is rooted on a weak position of accessibility planning in the political agenda, where mobility planning is still the main priority. In fact, only 3 out of 16 of the countries involved in this study are believed to have policy requirements for accessibility planning (Figure 16.1). 1 By and large policy still focuses on facilitating mobility as an end in itself (by developing transport systems), rather than seeing mobility as a means of granting access to opportunities (by a combination of transport and land use interventions). As explained in the introductory chapters of this book, and illustrated by the many instruments and applications that have followed, the difference is rather substantial. Also if we take a closer look at the European Directives on transport and mobility, although accessibility is currently referred as a political priority, the specific scope is generally limited to mobility of the physically impaired or to accessibility to and at public transport stops or stations. FIGURE 16.1 Policy Requirements to undertake an accessibility analysis. Source: Hull, A., Silva, C. and Bertolini, L. (Eds.) (2012). N=16 Countries of the 22 accessibility instrument developers surveyed in the Accessibility Instrument Survey (Hull, et al., 2012).
Accessibility-Based Evaluation of Transportation and Land-Use Planning: From Laboratory to Practice
2016
The concept of highway level-of-service (LOS) 1 and associated mobility metrics including congestion-related delays 2 and prospective value of travel time saved as incorporated in cost-benefit analyses 3 have for decades shaped the practice of transportation planning. 4 Mobility thinking has become so ingrained within the transportation planning profession that many evaluations of transportation projects focus on mobility-related level of service without discussing the rationale behind the level of service measure. The mobility-centered approach is operationalized in transportation planning's "predict-andprovide" formulation 5 in which planners model travel flows over transportation networks, simulate the impact of future land-use and population change on those flows, and identify opportunities to improve flows through targeted expansion of capacity. In practice, this has often has meant expanding highway links whose forecast volume-to-capacity ratios presage unacceptable degradation in LOS. This planning approach has been criticized for overestimating the certainty of modeling results, 6 imposing an overly narrow technical rationality on the transportation planning process 7 , and neglecting the futility of a strictly supply-based approach to transportation problems. 8 9 Less common is the critique of the standard transportation paradigm on the basis of its fundamental goal of preserving and expanding mobility, rather than accessibility. 10 This critique argues that planning and evaluation frameworks that are not grounded in the fundamental purpose of transportation threaten to generate perverse transportation outcomes.
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.
Transport Policy, 2005
The integration of transport and land use planning is widely recognized as essential to the achievement of sustainable development. The concept of accessibility-or what and how can be reached from a given point in space-can provide a useful conceptual framework for this integration. More specifically, a shift of focus in urban transport planning from catering for mobility to catering for accessibility helps see how more sustainable transport options can, under certain land use conditions, provide a competitive degree of accessibility that matches less sustainable options. The authors have used the concept of accessibility as a framework for the interactive design of integrated transport and land use plans in two areas of the Netherlands. The objective of these exercises was identifying solutions where economic, social, and environmental goals could be combined, defined as the achievement of 'sustainable accessibility'. The existing situation has been evaluated, and alternative plans have been developed. In this paper we reflect on these experiences and sketch the way forward, with a focus on the methodological aspects of the undertaking. In this respect, a major challenge is finding a workable balance between an accessibility measure that is theoretically and empirically sound and one that is sufficiently plain to be usefully employed in interactive, creative plan-making processes. q
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...
Transport Policy, 2002
To ensure more effective integration of development and transport planning, new national planning policy guidance in the UK requires greater consideration of accessibility issues. Although quantitative accessibility analysis is common in research, the practical application of these techniques in land use planning has been rare, and assessment has been restricted to qualitative considerations. The strong policy focus on accessibility increases the need for robustness, but practical quantitative techniques are still evolving. This paper describes a structured approach to accessibility analysis, as part of the development of a new structure plan for Edinburgh and the Lothians, and demonstrates how an ‘integration index’ can be developed from accessibility measures to help compare alternative approaches.
European Planning Studies
In both the scientific and professional community, the need to integrate transport and land-use policies in order to achieve more sustainable urban development is widely recognized. Accessibility can provide a conceptual focus for this integration because it relates to both features of the transport system (e.g. speed, and travel costs) as well as the land-use system (e.g. density and functional mix). The concept of accessibility is well known within the scientific literature. The understanding of how it can improve transport land-use planning integration in practice, however, is still limited. In order to address this gap between theory and practice, we discuss two case studies in the Netherlands in which policy-makers from both transport and land-use planning developed and used accessibility indicators to generate and select effective combinations of transport and land-use interventions. For each case, the type of accessibility indicators used and the way they contributed to an integrated assessment of the quality of the transport and land-use system and the different policy options that resulted from the assessment are discussed. Finally, we reflect on the potentials and limits of this approach, and on the opportunities and barriers for its implementation in day to day planning practice.
Considerations on the management of accessibility improvement impact on land use
Journal of Urban and Landscape Planning, 2018
This paper addresses a LUM (Land Use & Mobility) approach of accessibility improvement issues. It presents a deterministic radiography of the impact that a new transportation infrastructure has within its territory of influence, through the accessibility it provides. The study concludes on legislative and methodological improvements for developing a necessary, integrated LUM planning of accessibility, so as to achieve its highest capitalization and to mitigate its possible negative side-effects in the territory. The focus is on the key issues for developing a framework for a LUM planning of accessibility in the Romanian context.
CONSIDERATIONS ON THE MANAGEMENT OF ACCESSIBILITY IMPROVEMENT IMPACT ON LAND-USE (2018)
Journal of Urban and Landscape Planning - JULP, ISSN-L 2501-5591 (Online)=ISSN 2559-4141, 2018
This paper addresses a LUM (Land Use & Mobility) approach of accessibility improvement issues. It presents a deterministic radiography of the impact that a new transportation infrastructure has within its territory of influence, through the accessibility it provides. The study concludes on legislative and methodological improvements for developing a necessary, integrated LUM planning of accessibility, so as to achieve its highest capitalization and to mitigate its possible negative side-effects in the territory. The focus is on the key issues for developing a framework for a LUM planning of accessibility in the Romanian context.