A methodological approach for indicator-based sustainable transport assessment
Sustainable transport is now a popular goal of transport planning. As with any aspiration, systems and mechanisms are required to assess and gauge success in achieving this policy goal. There is increasing reliance on sustainable transport indicators as appropriate tools for this purpose. The usefulness and credibility of any indicator-based assessment will undoubtedly depend on the specific indicators utilised. As such, indicators must be selected carefully to maximise their contribution to the sustainable transport decision making process. A review of current applications of sustainable transport indicators has revealed however, that they are typically selected in an ad hoc and arbitrary fashion. Development of a framework that facilitates transparent and systematic indicator selection would therefore represent a significant advance in transport research. In that regard, this thesis presents the Evaluative and Logical Approach to Sustainable Transport Indicator Compilation (ELASTIC), a methodological framework which provides a flexible, participatory and systematic mechanism for identifying and selecting key sustainable transport indicators. The output of ELASTIC is the Transport Sustainability Profile (TSP), a small un-aggregated suite of sustainable transport indicators which together can provide a snapshot of the sustainability of a transport system. Using various multi-criteria and statistical techniques, ELASTIC applies a robust process to evaluate and select indicators based on their analytical soundness and their relevance to key objectives of sustainable transport. A generic and transferable tool, ELASTIC is capable of application at different geographical scales as well as to non-transport sustainability assessment. For the purpose of this research, the framework is demonstrated through application to England, UK where the judgements of relevant Academics and Transport Planners are elicited and entered into the ELASTIC framework to systematically select a subset of 15 indicators from an initial set of 200. By disaggregating the sample of stakeholders into regional groupings, different context-specific suites of indicators for the regional groupings were also derived. The demonstration confirms ELASTIC to be an inclusive and practical approach to compiling a suite of sustainable transport indicators specific to context and which reflects the unique values of key stakeholders.