W. Walker | Delft University of Technology (original) (raw)

Papers by W. Walker

Environmental Practice, 2006

Sustainable development has become a central objective of policy worldwide. However, although the... more Sustainable development has become a central objective of policy worldwide. However, although the term is widely used, there is little agreement on what it means in practice, and how progress toward it can be measured.

Infoplease. com Web site, …, 2003

Urban Transport XII: Urban Transport and the Environment in the 21st Century, 2006

Safety is of utmost importance in urban road traffic. Many studies reveal that speed is the major... more Safety is of utmost importance in urban road traffic. Many studies reveal that speed is the major factor contributing to road accidents. In the Netherlands, 50% of the speed offences and 65% of the accidents occur on urban roads. Research by the Dutch Ministry of Transport indicates that the elimination of speeding would reduce accidents and fatalities by 21% and hospitalized victims by 15%, and provide benefits to the Dutch economy of 300 million euros per year. Implementation of Intelligent Speed Adaptation (ISA) seems to be a promising way to meet these targets. Although ISA is a tested and proven technology, its implementation is impeded by many uncertainties, including its acceptance by drivers, its effects on driving behavior, and its effectiveness in real world driving conditions (as opposed to 'laboratory' conditions). As a result, policymakers need a way to implement ISA so that its safety benefits can be obtained despite the existence of uncertainties that cannot be reduced in advance. This paper proposes an innovative, adaptive approach for implementing ISA that would permit implementation to proceed while knowledge was gained about the uncertainties over time (i.e., the level of uncertainty was reduced). Under the adaptive approach, actions to deal with the certain vulnerabilities of the policy are implemented at the same time as the policy, and uncertain vulnerabilities are monitored and actions taken as required. This approach allows adaptations to the policy over time as knowledge about ISA is gained and critical events for ISA implementation take place. In particular we propose to begin by implementing ISA (Dynamic Voluntary) for young car drivers between 18-34 years of age and on unsafe roads i.e. urban roads (30 to 80km/h) and to prepare to adapt the policy over time.

This study was performed for the Directorate for Technology Policy, Ministry of Economic Affairs ... more This study was performed for the Directorate for Technology Policy, Ministry of Economic Affairs of the Netherlands. The two major purposes of the study were to (1) identify technologies of strategic importance to the Netherlands (based on a systematic global ...

Operations Research, 1994

This paper describes a four-month study performed for the Dutch Minister of Transport, Public Wor... more This paper describes a four-month study performed for the Dutch Minister of Transport, Public Works, and Water Management that examined the consequences of alternative policies for providing flood protection to the nontidal branches of the Rijn and Maas Rivers in The Netherlands. The paper focuses on estimating the flood damage that would occur under alternative safety standards, estimating the financial costs of alternative dike improvement strategies, and estimating the damage that would be inflicted on the landscape, natural, and cultural values along the rivers under each of these strategies. The primary objective of the study was to identify policies that would provide a high level of safety, would not cost too much, and would preserve as much as possible of the existing landscape, natural, and cultural values along the rivers. Less than six months after the completion of the study, the Dutch Parliament approved a new river dike policy that was based on the study's results.

Futures

Adaptive Policymaking (APM) is an approach for designing policies under conditions of deep uncert... more Adaptive Policymaking (APM) is an approach for designing policies under conditions of deep uncertainty. As such, it explicitly takes into account the limits of futures research methods. Although it was proposed over ten years ago (in 2001) and many cases of its use in designing policies for various policy domains have been published, APM is still considered a theoretical approach. In this paper we aim to close the gap between theory and practice by: (1) presenting an operationalization of APM aimed at developing dynamic adaptive policies with experts, (2) applying the operationalization to a real world policy problem involving traffic safety technology, (3) reporting not only on the resulting dynamic adaptive policy, but also on the workshop with experts that was used to develop this policy, in order to provide guidance to others interested in designing and implementing adaptive policies. The workshop was conducted with actors who would be expected to participate in the policymaking...

Technological Forecasting and Social Change, 2010

Many long-term transport policy decisions are made by assuming that (1) the range of possible fut... more Many long-term transport policy decisions are made by assuming that (1) the range of possible futures is known well enough to predict future changes to the transport system, (2) there is enough knowledge regarding the correct transport system model to estimate policy outcomes, and (3) there is enough knowledge regarding the importance stakeholders currently assign to the various outcomes or will assign in the future. However, for long-term transport policy decisions these assumptions can often not be made, since decision makers, analysts, and experts do not know or cannot agree on (1) how the future will develop, (2) the system models, and/or (3) the value system(s) to be used to rank alternative policies. This paper presents a 'dynamic adaptive' approach to policymaking for long-term transport policies that aims at overcoming the shortcomings of traditional approaches for handling deep uncertainty. It allows adaptations in time as knowledge is gathered. The approach is illustrated with dynamic adaptive policies for solving various long-term problems in the fields of road, rail, and air transport.

Building Blocks for Sustainable Transport, 2007

This research provides an understanding of the key drivers of freight transport demand, how they ... more This research provides an understanding of the key drivers of freight transport demand, how they affect demand, and how they can be influenced in order to achieve policy goals. The research consisted of a literature study and data analysis. Freight transport demand was studied at the decisionmaking level, since the amount and composition of freight transport demand is determined by a set of choices (e.g. shipment size and frequency, mode, time-ofday, route) made by a variety of decisionmakers. The key drivers of freight transport demand are Gross Domestic Product (GDP), consumer demand, economic structure, the logistics system, and the characteristics of the available modes of transport. Some of the drivers (e.g. GDP) are not reasonable targets for transport policies. However, many of the drivers can be influenced by policy in order to shape demand in more sustainable directions. These policies include changes in prices, regulations, infrastructure, traffic management, information provision, and subsidies, all of which affect one or more of the drivers or directly affect demand. The paper identifies the key drivers, and how each affects the various choices and the overall demand. It then discusses the possibilities and limitations of policy measures.

RAND is a nonprofit institution that helps improve policy and decisionmaking through research and... more RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND ® is a registered trademark. RAND's publications do not necessarily reflect the opinions or policies of its research sponsors.

Environment and Planning B: Planning and Design, 2014

Megaprojects are large, costly, complex infrastructure projects. To assess the financial viabilit... more Megaprojects are large, costly, complex infrastructure projects. To assess the financial viability of a megaproject, a cost—benefit analysis (CBA) is usually performed; the results depend upon the accuracy of the cost estimations and the predictive models used to forecast future demand for the use of the infrastructure. The outcomes of the models are very vulnerable to unexpected events. As a result, the CBA may become unreliable and give an unrealistic picture of the financial viability of a project. An alternative way of policy making that tries to take uncertainty into account is the dynamic adaptive policy (DAP) approach. This approach involves a systematic method for designing and implementing a policy over time that is based on a clear set of constraints and objectives and that involves monitoring the environment, gathering information, and adjusting and readjusting to new circumstances. The efficacy of this type of policy making has already been shown, but whether DAP leads t...

Operations Research, 1975

Proceedings of the 6th conference on Winter simulation - WSC '73, 1973

This paper describes a simulation model developed as a tool to aid deployment decision-making for... more This paper describes a simulation model developed as a tool to aid deployment decision-making for the New York City Fire Department. The model, written in Simscript I.5, has been used to evaluate alternative solutions to workload and response problems plaguing the City. These solutions involve new policies for locating, relocating and dispatching fire-fighting units to achieve a more effective utilization