Vincent Marchau

Classifying and communicating uncertainties in model-based policy analysis

Uncertainty is of paramount importance in modern day decision making. In response to this, it has been suggested that policy analysts have to be more careful in communicating the uncertainties that are inherent in policy advice. To support policy analysts in identifying uncertainties and communicating these uncertainties to decision makers, an uncertainty matrix was proposed by Walker et al. (2003), which synthesised various taxonomies, frameworks and typologies of uncertainties from different decision support fields. Since its publication, this framework has been applied to different domains. As a result, the framework has undergone changes resulting in a proliferation of uncertainty frameworks. This proliferation runs counter to the purpose of the original framework. This paper presents an extensive review of the literature that builds on Walker et al. (2003). In light of this, a synthesis is presented, which can be used to assess and communicate uncertainties in model-based policy analysis studies.

Assessing the efficacy of dynamic adaptive planning of infrastructure: results from computational experiments

In this paper we assess the efficacy of a dynamic adaptive planning (DAP) approach for guiding the long-term development of infrastructure. The efficacy of the approach is tested on the specific case of airport strategic planning. Utilizing a fast and simple model of an airport, and a composition of small models that can generate a wide spectrum of alternative futures, the performance of a dynamic adaptive plan is compared with the performance of a static, rigid implementation plan across a wide spectrum of conceivable futures. These computational experiments reveal that the static rigid plan outperforms the dynamic adaptive plan in only a small part of the spectrum. Moreover, given the wide array of possible futures, the dynamic adaptive plan has a narrower spread of outcomes than the static rigid plan, implying that the dynamic adaptive plan exposes planners to less uncertainty about its future performance despite the wide variety of uncertainties that are present. These computational results confirm theoretical hypotheses in the literature that DAP approaches are more efficacious for planning under uncertainty.

Uncertainty in the Framework of Policy Analysis

Synonyms: uncertainty, doubt, dubiety, skepticism, suspicion, mistrust, mean lack of sureness about someone or something. Uncertainty may range from falling short of certainty to an almost complete lack of conviction or knowledge especially about an outcome or result. Doubt suggests both uncertainty and inability to make a decision. Dubiety stresses a wavering between conclusions. Skepticism implies unwillingness to believe without conclusive evidence. Suspicion stresses lack of faith in the truth, reality, fairness, or reliability of something or someone. Mistrust implies a genuine doubt based upon suspicion. [Merriam-Webster Online Dictionary].

POLICY ASPECTS OF DRIVER SUPPORT SYSTEMS IMPLEMENTATION: RESULTS OF AN INTERNATIONAL DELPHI STUDY

Driver support systems are generally assumed to contribute to public traffic goals. However, much uncertainty exists about their future: technology development, market introduction and impacts on driver and traffic behaviour. An international Delphi study, collecting expert opinions on these issues, is describe this paper. In three rounds opinions were collected from 50 experts from USA, Japan and Europe. The article focuses on market introduction, driver behaviour, general barriers and policy options.

ISA implementation and uncertainty: A literature review and expert elicitation study

Each day, an average of over 116 people die from traffic accidents in the European Union. One out of three fatalities is estimated to be the result of speeding. The current state of technology makes it possible to make speeding more difficult, or even impossible, by placing intelligent speed limiters (so called ISA devices) in vehicles. Although the ISA technology has been available for some years now, and reducing the number of road traffic fatalities and injuries has been high on the European political agenda, implementation still seems to be far away. Experts indicate that there are still too many uncertainties surrounding ISA implementation, and dealing with these uncertainties is essential for implementing ISA. In this paper, a systematic and representative inventory of the uncertainties is made based upon the literature. Furthermore, experts in the field of ISA were surveyed and asked which uncertainties are barriers for ISA implementation, and how uncertain these uncertainties are. We found that the long-term effects and the effects of large-scale implementation of ISA are still uncertain and are the most important barriers for the implementation of the most effective types of ISA. One way to deal with these uncertainties would be to start implementation on a small scale and gradually expand the penetration, in order to learn how ISA influences the transport system over time.

User Perceptions and Preferences of Advanced Driver Assistance Systems

The introduction of electronic advanced driver assistance systems (ADASs) in road vehicles is expected to improve traffic efficiency and safety significantly. Successful implementation of these systems in the near future will largely depend on the willingness of people to buy and use these systems. This willingness is explored by estimating a model that specifies how ADASs are perceived in terms of contributing to personal driving goals and how these goals, in turn, influence overall preferences for ADAS. Therefore, drivers of cars and trucks throughout Europe had been requested to complete a stated-preference experiment in which they had to indicate to what extent they perceived that various ADAS alternatives would change their personal driving goals. In addition, drivers were requested to rate the selected ADAS descriptions in terms of overall attractiveness to have the described system in their vehicle. Structural equation modeling (SEM) has been applied to estimate simultaneously how the ADA subsystems are perceived in terms of personal driving goals and how the personal goals and price, in turn, affect overall preference. The results indicate that the different ADASs have different effects on the various personal goals. Furthermore, the results indicate that especially changes in safety and comfort levels affect overall preferences and to a lesser extent changes in travel time while fuel consumption has the least effect.

Intelligent transport systems and preferences for office locations

This paper explores the effect of three intelligent transport systems (ITS)-related transport concepts on location preferences of office-keeping organisations in urbanised areas. To measure these effects, a hierarchical information integration experiment was conducted in the Netherlands. Representatives of office-keeping organisations in selected city regions were questioned about the attractiveness of hypothetical ITS-based accessibility profiles of office locations. A general preference model was estimated to test the hypothesis that the introduction of ITS-based transport concepts will significantly influence the preferences of office-keeping organisations regarding office locations. It appears that all the included ITS attributes have a significant impact on the accessibility preferences of office-keeping organisations in urban regions. Moreover, location preferences change slightly after the introduction of the three ITS-related transport concepts.

Wireless Internet on Trains: Impact on Performance of Business Travelers

Wireless Internet service (WIS) is finding increasing implementation in the Netherlands via several markets. Recently, the idea has emerged of providing WIS through public transport services. The impact of WIS on train travelers, particularly on business travelers, is, however, unknown. In a study to examine this impact, respondents were surveyed to find out how WIS might affect their travel and work performance. Respondents were also questioned about their willingness to pay for WIS and their preferred WIS characteristics. In general, respondents were positive about WIS and were willing to spend an average of €3.17 [Eur 1 = U.S.

Dynamic Adaptive Approach to Transportation-Infrastructure Planning for Climate Change: San-Francisco-Bay-Area Case Study

1.28 (2006)] per trip for its use. Furthermore, they considered data security the most important WIS feature. Hence, it can be concluded that WIS deserves to be implemented in train services for business travelers as a means to enhance their travel and work performance during traveling.

Prospects for external sources of vehicle propulsion: Results of a Delphi study

Adaptation of existing infrastructure is a response to climate change that can ensure a viable, safe, and robust transportation network. However, deep uncertainties associated with climate change pose significant challenges to adaptation planning. Specifically, current transportation planning methods are ill-equipped to address deep uncertainties, as they rely on designing responses to a few predicted futures, none of which will occur exactly as envisioned. In this paper, we propose using dynamic adaptive planning (DAP), an emerging general strategic planning method, to account for deep uncertainties by building flexibility and learning mechanisms into plans that enable continuous adaptation throughout implementation. This paper first reviews uncertainty in general, introduces what is meant by deep uncertainty, and then introduces DAP. Then, DAP is applied to a case study of the Oakland approach to the San Francisco-Oakland Bay Bridge, which was initially assessed under the 2010–2011 FHWA Climate Change Vulnerability Assessment Pilot program, to illustrate how DAP could be applied as a response to climate change in the context of evolving transportation infrastructure adaptation planning practices in the United States. We conclude that DAP is well suited to account for the deep uncertainties of climate change in transportation and infrastructure planning, and provide suggestions for further research to better apply DAP in this field.