An empirical study on aggregation of alternatives and its influence on prediction in car type choice models

Transportation - Assessing and predicting car type choices are important for policy analysis. Car type choice models are often based on aggregate alternatives. This is due to the fact that analysts...     

Correlates of bicycling trip flows in Hamilton,Ontario: fastest,quietest, or balanced routes?

Transportation - Bicycling is an increasingly popular mode of travel in Canadian urban areas, like the Greater Toronto and Hamilton Area (GTHA). While trip origins and destinations can be inferred...     

Risk perception in the Norwegian shipping industry and identification of influencing factors

In the recent years, safety culture in relation to shipboard safety and organizational factors has received increasing interest within the shipping industry. This study examines this relationship, where risk perception is an indicator for shipboard safety. Data was derived from a survey carried out in 2006, where 1262 questionnaires were collected from 76 vessels. Explorative factor analyses were used to extract factors of safety culture. Analysis of variance was used to assess the associations between the safety cultural factors and demographic and organizational variables. Finally, linear regression analysis was carried out to assess the association between risk perception and safety culture, controlling for the influence of demographic and organizational variables; age, department, vessel type and nature of work. The results suggest that safety-oriented shipboard management style, performance of proactive working practices and good reporting practices all contribute to a better perception of shipboard safety, while a high demand for efficiency contributes to a more negative perception of the safety level. Further, safety is perceived as better when work is performed as a team. To gain a better understanding of risk perception and safety at sea, it would be helpful to further examine the characteristics and influences of teamwork.     

Cognitive cost in route choice with real-time information: An exploratory analysis

Real-time traffic information is increasingly available to support route choice decisions by reducing the travel time uncertainty. However it is likely that a traveler cannot assess all available information on all alternative routes due to time constraints and limited cognitive capacity. This paper presents a model that is consistent with a general network topology and can potentially be estimated based on revealed preference data. It explicitly takes into account the information acquisition and the subsequent path choice. The decision to acquire information is assumed to be based on the cognitive cost involved in the search and the expected benefit defined as the expected increase in utility after the search. A latent class model is proposed, where the decision to search or not to search and the depth of the search are latent and only the final path choices are observed. A synthetic data set is used for the purpose of validation and ease of illustration. The data are generated from the postulated cognitive-cost model, and estimation results show that the true values of the parameters can be recovered with enough variability in the data. Two other models with simplifying assumptions of no information and full information are also estimated with the same set of data with significantly biased path choice utility parameters. Prediction results show that a smaller cognitive cost encourages information search on risky and fast routes and thus higher shares on those routes. As a result, the expected average travel time decreases and the variability increases. The no-information and full-information models are extreme cases of the more general cognitive-cost model in some cases, but not generally so, and thus the increasing ease of information acquisition does not necessarily warrant a full-information model.     

Climate Change and Coastal Management Decisions: Insights from Christchurch Bay,UK

The integration of climate change adaptation considerations into management of the coast poses major challenges for decision makers. This article reports on a case study undertaken in Christchurch Bay, UK, examining local capacity for strategic response to climate risks, with a particular focus on issues surrounding coastal defense. Drawing primarily on qualitative research with local and regional stakeholders, the analysis identifies fundamental disjunctures between generic concerns over climate change and the adaptive capacity of local management institutions. Closely linked with issues of scale, the problems highlighted here are likely to have broad and continuing relevance for future coastal management elsewhere.