An activity-based approach for scheduling multimodal transit services

This paper proposes a new activity-based transit assignment model for investigating the scheduling (or timetabling) problem of transit services in multi-modal transit networks. The proposed model can be used to generate the short-term and long-term timetables of multimodal transit lines for transit operations and service planning purposes. The interaction between transit timetables and passenger activity-travel scheduling behaviors is captured by the proposed model, as the activity and travel choices of transit passengers are considered explicitly in terms of departure time choice, activity/trip chain choices, activity duration choice, transit line and mode choices. A heuristic solution algorithm which combines the Hooke–Jeeves method and an iterative supply–demand equilibrium approach is developed to solve the proposed model. Two numerical examples are presented to illustrate the differences between the activity-based approach and the traditional trip-based method, together with comparison on the effects of optimal timetables with even and uneven headways. It is shown that the passenger travel scheduling pattern derived from the activity-based approach is significantly different from that obtained by the trip-based method, and that a demand-sensitive (with uneven headway) timetable is more efficient than an even-headway timetable.     

State-of-the art of freight forecast modeling: lessons learned and the road ahead

In this paper we review freight forecasting models and current advances and needs with respect to data and model development. We then present a case study to suggest which models should be developed for the State of California in the US. We suggest several alternatives including an aggregate commodity flow model, a disaggregate regional logistics model and a hybrid regional logistics model with a truck touring model. We point out however, that the data requirements for the latter model would be extensive. In addition, the development of hybrid models, for example progress in the integration of regional logistics models with urban truck touring models, will introduce new problems such as reconciling the outputs of multiple models for consistency.     

Estimation method for railway passengers’ train choice behavior with smart card transaction data

Smart card systems have become the predominant method of collecting public transport fares in Japan. Transaction data obtained through smart cards have resulted in a large amount of archived information on how passengers use public transportation. The data have the potential to be used for modeling passenger behavior and demand for public transportation. This study focused on train choices made by railway passengers. If each passenger’s train choice can be identified over a long period of time, this information would be useful for improving the customer relationship management of the railway company and for improving train timetables. The aim of this study was to develop a methodology for estimating which train is boarded by each smart card holder. This paper presents a methodology and an algorithm for estimation using long-term transaction data. To validate the computation time and accuracy of the estimation, an empirical analysis is carried out using actual transaction data provided by a railway company in Japan. The results show that the proposed method is capable of estimating passenger usage patterns from smart card transaction data collected over a long time period.     

A modelling system to simulate goods movements at an urban scale

The paper reports a modelling system to simulate goods movements at an urban scale. It allows joint analysis of choices made by end-consumers (assumed to be families) and retailers. These movements are examined at two levels: analysis of commodity flows, in terms of quantity, generated by the consumption of commodities; analysis of commodity flows, in terms of vehicles, due to restocking. The first level allows us to calculate the goods quantity flows due to consumption and restocking; the second level allows us to determine the service, vehicles used and target time, as well as the route chosen for restocking sales outlets in order to estimate vehicle flows on the urban/metropolitan transportation network. The modelling system is a multi-step model and considers a disaggregated approach for each decisional level.     

Equality of bargaining power in contracts for international liner shipping

Mandatory rules exist in contracts for international liner shipping primarily because of imbalances and non-equity in the allocation of contract responsibilities. The superior bargaining position owned by the carriers depends largely upon liner market monopoly levels, the supply and demand balance between the shipper and carrier, and the cargo volume size of the shippers. With the development of shipping technologies, mode of transport, and shipping competition policy, the unequal comparison of bargaining forces between shippers and carriers changes. When the existing mandatory rule was deemed no longer necessary due to changing circumstances, legislation requirements to restore freedom to contract became apparent. When both sides have equal bargaining power, adoption of the principle of freedom of contract for their business relationships is suitable. The Rotterdam Rules concerning freedom of volume contract construction is based on equal bargaining powers between both sides and responds to the evolving situation of the industry. The Rules represent the development trend of today’s theory of contracts for international liner shipping and the demand for legal and institutional changes.     

Barriers for adoption of energy efficiency operational measures in shipping industry

According to the Third Greenhouse Gas (GHG) Study 2014 of International Maritime Organization (IMO), the total emission in 2012 are estimated to be 949 million tonnes which is 2.7% of global CO₂ emission by total shipping and expected to increase from 2012 levels by 50–250% by 2050. Significant changes are needed to all industry by implementation of energy efficiency design and operational measures to meet existing and future global emission reduction targets. Although the fuel cost-reducing effects of some energy efficiency measures and new technologies are well established and matured, shipping companies appear reluctant to adopt them. Besides, it is observed that the stakeholders are directly or indirectly involved for implementation of energy efficiency measures in shipping industry. Therefore, the objective for this study was to identify the barriers to energy efficiency operational measures by a qualitative survey among various stakeholders from all corners of shipping industry. It has been found in the research that the barriers for implementation of all cost-free operational measures are almost the same such as lack of information of the measure, lack of awareness and competence of ship crews and operation difficulties which are in nature of information and technical barriers. But financial issue and owner’s interest are the key barriers for some other operational measures which are related to costing and need investment for implementation.     

Empirical Equilibrium Beach Profiles Along the Eastern Tombolo of Giens

Beaches along the eastern branch of the Giens double tombolo are subject to coastal erosion. Prediction of the behavior of the beach profile configuration in response to natural and anthropogenic changes using the concept of equilibrium beach profile (EBP) could be useful in finding the most suitable measure to address the erosion problem. Field investigation data of 11 beaches along the eastern tombolo were supplied for this study, and a nonlinear fitting technique was applied to estimate the best parameter values of seven empirical formulations of the relevant EBP. All of the observed beach profiles could be described by a single function, but a single EBP was inadequate to represent all of the beach profiles observed. The variation found could be explained in terms of longshore variation of bathymetry, sediment size, and wave parameters. Analysis of the validity of the EBPs revealed that a representative EBP of each beach is governed by different equilibrium parameters.     

Effect of Sea Level Rise and Offshore Wave Height Change on Nearshore Waves and Coastal Structures

In 1994, Townend proposed a method to calculate the relative changes in various wave characteristics and structure-related parameters due to sea level rise for regular waves. The method was extended to irregular waves by Cheon and Suh in 2016. In this study, this method is further extended to include the effect of future change in offshore wave height and the sea level rise. The relative changes in wavelength, refraction coefficient, shoaling coefficient, and wave height in nearshore area are presented as functions of the relative changes in water depth and offshore wave height. The calculated relative changes in wave characteristics are then used to estimate the effect of sea level rise and offshore wave height change on coastal structures by calculating the relative changes in wave run-up height, overtopping discharge, crest freeboard, and armor weight of the structures. The relative changes in wave characteristics and structure-related parameters are all expressed as a function of the relative water depth for various combinations of the relative changes in water depth and offshore wave height.     

Apps,activities and travel: an conceptual exploration based on activity theory

With the continuous advancement of (mobile) ICT devices and applications, their impact on travel, activities and time use becomes more diverse. This holds in particular for apps developed for mobile devices (smartphones). In this paper, we argue that the effect of ICT on travel and activities should be analysed at the level of a single specific device or application, rather than for broad classes of ICT devices. We propose activity theory as a framework to analyse the impact of smartphone apps on travel and activities. Activity theory describes how subjects apply tools (such as apps) to work on an object and achieve an outcome that is in line with the subject’s motive. The application of the tool is embedded in an activity system which includes a community, formal and informal rules and in which a division of labour exists. We apply activity theory to analyse the effects of Whatsapp and travel feedback apps, based on existing literature about these apps. The analyses suggest that the activity systems of each app differ greatly in terms of object, motive, outcomes, community and rules, with implications for their use and impact. Both apps have an impact on travel, but differ with respect to whether this effect is intentional. For both apps contradictions in the activity system can be identified, which may give rise to further development of the activity system. These seem, however, to be largest for travel feedback apps. Based on our exploration, we argue that quantitative research on the impact of apps should be complemented by qualitative research based on activity theory. In particular, activity theory may help to gain a better understanding of underlying mechanism by which apps influence travel, to strengthen the theoretical underpinning and interpretation of the results of quantitative research and to explore changes in the development and use of apps and their impact on travel behaviour.