Beyond Mobility - Understanding and Comparing Urban Accessibility in European Cities
Charlotte Brannigan, Ricardo Energy & Environment, Guy Hitchcock, Ricardo Energy & Environment
A State of the Art Review to advance the understanding of European urban accessibility, including urban accessibility definition, metrics and assessment, and potential accessibility indicators for use within a European Urban Mobility Scoreboard.
The European Commission (Directorate General for Mobility and Transport) launched a study to increase the understanding of urban accessibility in order to improve the functioning of urban areas and make the transport system in Europe’s urban areas more efficient. A key element of the study was a State of the Art Review of past and current research and practice on ‘urban accessibility’ in Europe and further afield. The review has been compiled based on an assessment of the relevant literature and complemented by stakeholder engagement, including interviews and a workshop with key experts and academics in the field of accessibility. The review addresses the definition and scope of urban accessibility, accessibility metrics in use, modelling techniques and their applications, and policy initiatives affecting accessibility.
It is clear from the literature that many definitions of accessibility currently exist. However, in broad terms the concept of ‘urban accessibility’ can be defined as the ease of reaching goods, services, activities and destinations in urban areas, including factors such as mobility options, travel information, transport network connectivity, land use patterns and cost for both passengers and freight. This definition encompasses the four commonly identified dimensions of accessibility: land use (where activities are), transport (how to get to activities or locations), individual (needs, capabilities and perceptions) and temporal (availability of the opportunity and the individual).
There are an extremely diverse range of measures and indicators that are currently used or have been identified by policy makers and academics in the pursuit of assessing and subsequently improving urban accessibility. These include infrastructure, location, person and utility-based indicators. The review identifies and explores in more detail the advantages and disadvantages of the indicators.
‘Mobility’ is also often referred to in the context of accessibility. However, mobility differs from accessibility in that it refers to the movement of people and goods, whereas accessibility encompasses wider issues, such as the consideration of the opportunities that are enabled by mobility. By considering accessibility rather than just mobility a more comprehensive approach can be taken to urban transport planning, generating increased social and economic benefit.
The inclusion of accessibility indicators in a European Urban Mobility Scoreboard would facilitate comparison between urban areas and over time, and promote the use of accessibility beyond just mobility in urban transport planning. In this context it is evident that some accessibility indicators could be more useful in developing a scoreboard than others, and that there will be a trade-off between accuracy, and ease of implementation and interpretation. Accuracy is obviously necessary if comparisons between cities and over time are to be informative. But ease of interpretation is also important if the scoreboard is going to have an influential effect on policymakers.
A key determinant to the success of accessibility indicators at the Europe level is data – including its format, availability and ease of collection. In order to make comparisons between European cities, the data will need to be readily available to most cities, with the potential to be collected at the European level. Whilst key transport and land-use accessibility data is likely to be readily available (e.g. key transport routes, services and interchanges and location of key opportunities and activities), data relating to the individual and temporal dimensions of accessibility often involves more labour intensive methods of obtaining data (e.g. undertaking of stated-preference surveys, travel diaries, consulting timetables, traffic monitoring, censuses, intelligent transport systems, interviews etc.).
Consideration will also need to be given to the substantial area-level differences between individuals in different parts of the EU. Indicators need to allow comparison of accessibility (e.g. time or distance to access opportunities) between cities, whilst not providing judgement on what is considered to be acceptable, or desirable. Given these considerations the most likely candidates for a European level indicator(s) on accessibility are location-based measures in terms of simple travel distances/times to opportunities. Although the use of accessibility measures in a European Urban Mobility Scoreboard would raise the profile of accessibility, it may prove difficult to distil complex accessibility issues into concise indicators over an area as diverse as Europe.
Association for European Transport