Karel Martens

Travel time savings, accessibility gains and equity effects in cost–benefit analysis

ABSTRACT The growing interest in the equity dimensions of transport planning has resulted in increasing criticism on the dominant assessment methodology of transport projects: cost–benefit analysis (CBA). In this paper, we focus on travel time savings, given their importance in the assessment of transport projects and the sometimes fierce equity-related citicism on their inclusion in project appraisal. We identify five equity effects related to the use of travel time savings in CBA. Each of these equity effects implies that transport projects serving the majority population are highly likely to perform better in CBA than comparable projects serving disadvantaged population groups. We subsequently explore whether the replacement of travel time savings by accessibility gains can address the identified equity effects. We observe that this only holds for two of the five equity effects, while a third effect can be mitigated through the introduction of the notion of diminishing marginal return in the valuation of accessibility gains. We conclude that the mere introduction of accessibility gains is in itself insufficient to address all equity effects related to the application of travel time savings within the CBA framework.

Urban parking space reservation through bottom-up information provision: An agent-based analysis

Abstract The aim of this paper is to study the impacts of a reservation system for on-street parking. Such a system provides drivers looking for on-street parking with information on available parking spaces, thereby possibly reducing the need to cruise for parking and the accompanying negative externalities. The performance of the proposed system is studied using a highly detailed spatial agent-based simulation. The results of the simulations show that users of a reservation system benefit in terms of reduced search time and reduced walking distance under virtually all simulated circumstances. However, societal benefits are not as clear-cut. The benefit in search time for the users of the system comes at a cost to the regular drivers, which see a nearly identical increase in search time. In contrast, the positive impact on walking distance hardly influences walking distance for regular drivers. Hence, we conclude that the introduction of a reservation system for on-street parking results in a more efficient distribution of available parking spaces among drivers searching for parking.

Integrating equity in transportation project assessment: a philosophical exploration and its practical implications

ABSTRACT This paper provides an overview of the conceptual essence of a number of justice theories and their possible consequences for transport project appraisal. In this paper, we discuss three alternative philosophical approaches to the still-dominant approach of utilitarianism: Rawls’s approach, Walzer’s approach, and the capability approach (CA), as they have different practical implications. We discuss which of these approaches could potentially give guidance to transportation appraisal, and which approaches are not suited for this purpose. We demonstrate the use of the CA and compare it to utilitarianism in a case study, and discuss the implications of adopting the former for transport evaluation and policy.

Impact of relocation strategies for a fleet of shared automated vehicles on service efficiency, effectiveness and externalities

The introduction of taxi-like transit services operated by shared automated vehicles comes into sight with the development of vehicle automation. In this paper, the operation of such a service is simulated for a generic grid network in order to determine the impact of different relocation strategies for idle vehicles on passenger waiting time, empty mileage and parking needs. The tested strategies consist of remaining idle at the latest drop-off location, returning to the initial position, relocating to a random location, relocating according to anticipated demand or relocating to a zone with a low vehicle supply. For the simulated case study, remaining idle outperformed the other relocation strategies in terms of service efficiency and service effectiveness, while the strategy of evenly or randomly dispersing vehicles over the network lead to largest reduction of the number of parked vehicles per link, and the strategy of anticipating demand to largest reduction of deadheading mileages.

Book review: Culp, Julian. 2014: Global Justice and Development

Culp, Julian. 2014: Global Justice and Development. Basingstoke: Palgrave MacMillan. 215 pp. 7 chapters. £63, ISBN 978–1-137–38992–3 (hardcover). £47.99, ISBN 978–1-137–38993–0 (eBook).