Abstract:Although a large body of literature has been produced on the theoretical definitions and measurements of accessibility, the extent to which such indicators are used in planning practice is less clear. This research explores the gap between theory and application by seeking to understand what the new wave of accessibility instruments (AIs) prepared for spatial and transport planning practice purports to offer the users of AIs. Starting from the question of how urban and transport planners are designing AIs, the article analyzes and describes the AIs developed over the last decade (mainly in Europe), offering a structured overview and a clear categorization of how accessibility measures can be applied. The paper identifies AI characteristics, and considers their usability, based on AI developer perceptions.
IntroductionAccessibility instruments (AIs) are a type of planning support system (PSS) designed to support integrated land-use transport analysis and planning through providing explicit knowledge on the accessibility of land uses by different modes of transport at various geographical scales. They measure, interpret and/or model accessibility and are developed to support the many research tasks involved in planning practice (analysis, design support, evaluation, monitoring, etc.). Although there exists an extensive literature on the analysis and the classification of accessibility measures and indicators incorporated in these AIs (Geurs and van Eck 2001;Geurs and van Wee 2004), less attention has been paid to the planning issues that they seek to support or to their usability and employability for the various planning goals in actual practice. This research aims to fill this gap and provide insights on the two following research questions: How has the new wave of accessibility instruments (AIs) prepared for spatial and transport-planning practice been designed? What is the usability of these planning instruments as perceived by their developers? To provide an answer to these questions, the paper draws on the outcomes of , accessibility analysis and instruments offer a highly suitable framework to support the development of combined land-use and transport strategies, so as to achieve the coordination and synergy required to attain city sustainability goals (Holden 2012;Stead, Geerlings, and Meijers 2004). Indeed, a focus on accessibility makes the overall goal of the land-use and transport system explicit and offers a direct link between the characteristics of flows (i.e., speeds and travel time) and the characteristic of places (i.e., the number of relevant activities in a given area). Because of these features, it represents a potentially powerful approach that planning practitioners can employ to develop and test effective strategies for sustainable cities (Straatemeier 2008), and that could act as good accelerators for a better coordination between urban and transport planning.The second reason for focusing on AIs, and in particular on their usability in planning practice, is that although both the...