Morten Skou Nicolaisen

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.

An International Review of Ex-Post Project Evaluation Schemes in the Transport Sector

There are a number of ex-post (or post-opening) project evaluation schemes used by national transportation authorities in, among others, England, Scotland, France, Australia, New Zealand, Japan, Norway and the US. Additionally, many of the multilateral and bilateral lending institutions, such as the World Bank, the European Bank for Reconstruction and Development, the Inter-American Development Bank and the Asian Development Bank conduct ex-post project reviews of transport projects in the rail and road sectors. This paper presents a literature review of the various ex-post evaluation schemes in order to establish a state-of-the-art in ex-post road and rail project evaluation, develops an analytic typology of ex-post evaluation schemes and finally presents an in-depth case study of two ex-post evaluation schemes in Norway and England in order to provide a more detailed analysis of the process, structure and policy learning potential within ex-post project evaluation. In comparison to the extensive focus on ex-ante project appraisal, ex-post evaluations have received significantly less attention from academics and practitioners alike. The main findings are as follows: (1) Despite the widespread use globally of ex-post evaluation schemes in the transport sector, there remain significant differences in quality, coverage and comprehensiveness of the schemes. There is a striking lack of standardised methods of conducting ex-post evaluations at the national level, inhibiting the comparability and learning potential; (2) Even with legal mandates and decades of practice, data archiving and retrieval is a widespread problem for national transport planning agencies and (3) How to handle the counter-factual option (i.e. do-nothing/do-minimum/null option) is still very much an open question, which has significant impacts upon the forecasted and outturn benefit/cost ratios and environmental/social impacts.

Travelling together alone and alone together: mobility and potential exposure to diversity

Abstract Quantity and quality of social relations correlate with our happiness and physical health. Our (feeling of) connectedness also matters for the efficacy and functioning of communities and societies as a whole. Different mobility practices offer different conditions for being exposed to other people and the environment. Such exposure influences a sense of being connected to places, communities and societies. In transport planning practice and research, these relations are slowly getting attention. In this paper, we develop an analytical framework that offers a comprehensive understanding on if and how one’s experiences of being on the move influence the ability of an individual to develop a sense of connectedness. We develop hypotheses about these possible relations, that link literatures from mobilities research and sociology to advance transport planning research and practice. First, we discuss how the experiences of being mobile using different transport modes set different stages for the potential exposure to a diversity of socio-spatial environments. Second, we translate this into an analytical framework for understanding the relationships between connectedness and using different mobility modes. In the final part of the paper, we illustrate this by operationalising a number of potential indicators of connectedness (as dependent variables).