Patrick Arthur Driscoll

Ex-Post Evaluations of Demand Forecast Accuracy: A Literature Review

Abstract Travel demand forecasts play a crucial role in the preparation of decision support to policy-makers in the field of transport planning. The results feed directly into impact appraisals such as cost–benefit analyses and environmental impact assessments, which are mandatory for large public works projects in many countries. Over the last few decades, there has been increasing attention given to the lack of demand forecast accuracy. However, since data availability for comprehensive ex-post appraisals is problematic, such studies are still relatively rare. This study presents a review of the largest ex-post studies of demand forecast accuracy for transport infrastructure projects. The focus is threefold: to provide an overview of observed levels of demand forecast inaccuracy, to highlight key contextual and methodological differences between studies and to highlight key focus areas for future research in this field. The results show that inaccuracy remains problematic for road, rail and toll projects alike, but also how the lack of methodological clarity and consistency calls for a careful interpretation of these results. Mandatory, systematic ex-post evaluation programmes are suggested as a necessary tool to improve decision support, as data availability for ex-post studies is often remarkably poor even for internal audits.

Is the future of mobility electric?: Learning from contested storylines of sustainable mobility in Iceland

Planning for sustainable mobility is a complex and demanding task and the knowledge of how to trade off multiple, often conflicting, goals is not entirely clear. One of the most contentious and confounding issues in the context of urban planning has been, and continues to be, the place of the automobile within the evolving sustainable mobility paradigm. The recent emergence of strong policy and planning support for the introduction of electric vehicles raises thorny questions as to whether or not this development will be complementary to, or conflicting with, other sustainable mobility planning goals, such as the pursuit of compact cities, restrictions on automobiles, promotion of walking and bicycling, and support for public transport. The results of a recent pilot study conducted in the Reykjavik city region suggest that a strategy of provision for electric vehicles on a large scale may represent a continuation of the dominant transport engineering approach, drawing scarce financial and institutional resources away from path-breaking measures such as the efforts to create denser development patterns and promote non-motorized and public forms of transport.

Breaking Carbon Lock-In: Path Dependencies in Large-Scale Transportation Infrastructure Projects

The central focus of this paper is to highlight the ways in which path dependencies and increasing returns (network effects) serve to reinforce carbon lock-in in large-scale road transportation infrastructure projects. Breaking carbon lock-in requires drastic changes in the way we plan future transportation infrastructure projects, and documentary evidence presented here from the metropolitan regions of Copenhagen, Denmark and Portland, USA, indicate that there may be a discontinuity in the system of automobility (Urry, 2004), thereby increasing the likelihood that such drastic measures may in fact be successfully realized.

Young Academics Special Theme Issue: Perspectives on Planning Shifts, Challenges and Methodologies

How are young planning academics responding in their research to the grand economic, societal and environmental challenges posed by globalization, megacities, resource scarcity, rapid shifts in technology, increasing urbanization and climate change? At the same time, how is the planning discipline responding to the rapid transformation of cities and urban regions in contexts where spatial scales are increasingly blurred and sectoral planning has in some places largely supplanted national planning systems? Some of the answers emerge in the seven articles contained in this special theme edition of Planning Practice and Research. They comprise a storyline suggesting that urban and regional planning is under constant change, increasingly grasping innovative tools, technologies and stakeholder engagement, all of which push into new disciplinary areas while providing alternative insights into the inherent complexity of planning issues. If nothing else, this selection of articles serves to illustrate the need for researchers, educators and practising planners to cross-fertilize each other’s domains of expertise. This will help to counter disciplinary tunnel vision and keep planning relevant in age where many of the new ideas and visions are emerging from non-traditional planning areas such as behavioral economics, ICT, biology, physics and media studies. While it is widely acknowledged that early career researchers are the Stakhanovites of the modern academic paper factory, there are precious few arenas that are dedicated to publishing their original work. We are therefore grateful to Planning Practice and Research for opening up to AESOP Young Academics (YA) and hope that such an endeavour can become a regular feature of a number of planning journals. This AESOP YA special edition attempts to shed light on some of the grand challenges by highlighting the efforts and perceptions of some