Chengxi Liu

Weather variability and travel behaviour – what we know and what we do not know

ABSTRACT Given that severe weather conditions are becoming more frequent, it is important to understand the influence of weather on an individual’s daily activity-travel pattern. While some previously rare events are becoming more common, such as heavy rain, unpredicted snow, higher temperatures, it is still largely unknown how individuals will change and adapt their travel patterns in future climate conditions. Because of this concern, the number of research studies on weather and travel behaviour has increased in recent decades. Most of these empirical studies, however, have not used a cost–benefit analysis (CBA) framework, which serves as the the main tool for policy evaluation and project selection by stakeholders. This study summarises the existing findings regarding relationships between weather variability and travel behaviour, and critically assesses the methodological issues in these studies. Several further research directions are suggested to bridge the gap between empirical evidence and current practices in CBA.

Evolution of Satisfaction with Public Transport and Its Determinants in Sweden: Identifying Priority Areas

Measurement and analysis of satisfaction with public transport services facilitate service performance monitoring, market analysis, benchmarking, and the identification of priority areas. The systematic and regular collection of information concerning satisfaction enables investigation of how passengers’ satisfaction and its determinants change over time. These changes may be driven by changes in service quality or shifts in passengers’ expectations and preferences. This study analyzed how satisfaction with public transport and its determinants evolved over time in Sweden in the years 2001 to 2013. The determinants of satisfaction were identified by factor analysis and the estimation of multivariate satisfaction models. The superposition of these findings culminated in a dynamic passenger satisfaction priority map that allowed the identification of priority areas on the basis of observed trends in satisfaction with service attributes and their respective importance. The deterioration of overall satisfaction with public transport in Sweden in recent years has been driven by a decrease in satisfaction with customer interface and length of trip time. These two service aspects, as well as operation, were found to be key determinants of overall satisfaction that users consistently rated among the least satisfactory. The results of this study will support service providers in designing measures that will foster satisfaction in the future.

Jointly modelling individual’s daily activity-travel time use and mode share by a nested multivariate Tobit model system

ABSTRACT In this study, a nested multivariate Tobit model is proposed to model activity and travel time use jointly. This proposed model can handle: (1) The corner solution problem; (2) time allocation trade-offs among different types of activities; and (3) travel being treated as a derived demand of activity participation. The model is applied to the Swedish national travel survey (NTS). Evidence of the potential positive utility of travel time added on non-work activity time allocation in the Swedish case is also found. The proposed model is compared to an MDCEV model specification. The results show clear differences in marginal effect estimates. In terms of prediction, the nested multivariate Tobit model shows a slightly worse performance on the hit rate measure than the MDCEV model combined with a stochastic frontier model, but shows a slightly better performance on the SMAPE measure.