Hiroshi Shimamoto

A Game Theoretic Approach to the Determination of Hyperpaths in Transportation Networks

In transit assignment, the common lines problem leads to the notion of a hyperpath, which is a set of paths that when used according to the “take whichever attractive line arrives next” strategy minimises the expected travel time. Similarly, the game theoretic approach to risk-averse traffic assignment leads to the generation of a set of paths which minimises expected travel time when a pessimistic assumption is made about on-trip events. The equivalence between the hyperpath of transit assignment and the set of paths generated by a multi-agent, zero sum game is shown in this paper. In particular, game theory is used to show that the path split probabilities proposed by Spiess and Florian (1989) are optimal for the risk-averse traveller who needs to make an on-the-spot decision between alternative routes. An alternative two-agent (single demon), zero-sum game is considered. The results of the multiple- and two-agent games are compared on a small example network, showing that the single demon game can lead to denser hyperpaths.

Estimating Weights of Times and Transfers for Hyperpath Travelers

In high-frequency transit networks, travelers are often assumed to reduce their travel time by identifying sets of attractive lines. This concept was used in the development of most transit assignment models. Whether transfer penalties and waiting times are more highly valued than onboard travel times largely has been ignored in these assignment models. The literature on the estimation of the value of time for public transport passengers also ignores the complexity of choices faced by transit travelers in large cities. An effort to close this gap addressed the question of whether different passenger groups choose different strategies at stops. A web-based survey was conducted, and data from 597 individuals from various countries were obtained. Hyperpath selection was formulated as a discrete choice model, and the relative weights were estimated. Nested logit models were used to consider the correlation between alternatives within the hyperpath. Results indicated that individual specific attributes significantly influenced passengers selection of hyperpath.

A trip-chain-based combined mode and route-choice network equilibrium model

ABSTRACT This paper proposes a trip-chain-based mode and route-choice network equilibrium model that considers the ‘common lines problem’ in transit assignment. The proposed model assumes the nested-logit type of mode and route-choice structure for the travellers’ mode and route choice. The proposed model is formulated using the variational inequality problem, and the relaxation method is applied to solve the proposed model. Finally, the proposed model is applied to hypothetical networks, and confirms that the differences in the total mode share, link flows, and link travel times between the proposed model and the traditional trip-based assignment model are not large. We also confirmed that the some trip-chains differed considerably in mode share.

Evaluation of tsunami evacuation planning considering vehicle usage and start timing of evacuation

ABSTRACT This paper proposes a prescriptive model to formulate and evaluate a tsunami evacuation. The proposed method firstly establishes the evacuation scenario, which consists of defining the destinations of the evacuees, the starting time for evacuation and the evacuation mode. This scenario formulation is achieved by solving a linear programming problem. Subsequently, the scenario is evaluated by a time-dependent, multiclass assignment model. The proposed methodology was applied to the coastal area in Osaka city, Japan. Our main policy implications regard the permission of automobile usage for evacuation, a highly discussed issue in Japan. The results illustrate that some car usage can be allowed to facilitate fast evacuation but that excessive usage should be avoided under some conditions. We further suggest that it is not only the rate of car usage but also the timing of the usage of automobiles for evacuation that can be critical.

Special issue on transport dynamics of disruptions

This special issue originated with the organisation of the 6th International Symposium on Transportation Network Reliability (INSTR), which was held in August 2015 in Nara, Japan. The INSTR series is the premier gathering of the world’s leading researchers and professionals interested in transportation network reliability, where they discuss both recent research and future directions in this increasingly important field of research. This special issue includes five papers on the state of the art in research dealing with transport dynamics of disruptions, with a focus on public transportation reliability. Althoughmost of these papers are drawn from those presented at the INSTR 2015 symposium, an open call for papers was alsomadewhich attracted several submissions. All submitted papers were rigorously reviewed to ensure the quality and correctness of their content In the first paper, by O. Cats and E. Jenelius investigate the impacts of a range of public transport network performance. They introduce the idea of a vulnerability curve and related metrics to investigate the relationship between network performance and the degradation of line or link capacities. The impacts of capacity reductions are assessed using a non-equilibrium dynamic public transport operations and assignment model. The proposed method is applied to a full-scan analysis of planned temporary line-level capacity reductions and an analysis of unplanned link-level capacity reductions on the most central segments in the multi-modal rapid public transport network of Stockholm. The results of the case study suggest that policy-makers and service operators should devote disproportional attention to major capacity reductions in case of planned line disruptions in the study network. In the second paper, by Lu and Dong propose a method to estimate travel times based on data collected from roadside radar sensors, considering car-following behaviour and spatially correlated traffic conditions. The proposed travel time estimation model can well capture the temporal pattern of travel time and its distribution. The paper concentrates on the analyses of link-level travel times based on spatio-temporal radar data and the random variable distribution approach, where the fits of various probability density functions are sought. Travel time estimations from radar data are mapped to relevant distributions and are correlated with probe data. Based on the results, as route travel time reliabilities derived from link-level distributions, it is concluded that the proposedmodel outperforms probe data in terms of mapping travel time patterns and approximating their distributions. The third paper, by Nosedal-Sanchez and Piaera, addresses a causal analysis of the airport turnaround processes, which is a key factor to enhance the air traffic management reliability. Cause–effect relationship analysis demands for a knowledge representation technique that considers the stochastic, dynamic and synchronous nature of the turnaround process, and allows representing both the structure and the different ways in which the sub-processes can be influenced. It is important that the causal analysis of the different perturbations has been measured in order to provide insights for better design of policies and strategies for a robust and efficient turnaround that could mitigates undesirable dynamics or at least detect them in advance and enhance the robustness of the turnaround and their related processes and actors performance with direct and indirect impact on ATM system reliability The fourth paper in this special issue, by Xiong at el., develops an agent-based approach to modelling travel behaviour under uncertainty and information provision, motivated by the aforementioned theoretical and practical issues that arise in a simulation-based approach. The methodology

Estimating the flow of recyclable items and potential revenue at a waste bank: the case in Malang City, Indonesia

In some Southeast Asian countries, there has been a new approach to waste recycling called “waste banks,” which aims to encourage community members to recycle and develop sustainable waste management. This study investigated the waste banks using Bank Sampah Malang (BSM) in Malang City, Indonesia, as a case study. The aim of this study was to determine the flow of recyclables and which recyclables should be separated by participants of waste banks to effectively earn revenue. The second aim was to estimate the potential revenue from recyclables in the waste bank system. Detailed data, such as weight by recyclable material type, were collected from January 2 to April 4, 2013. There were five groups that participated at BSM, one of which [communities (COM) consisting of a minimum of 20 households] contributed the majority of the recyclables that were submitted to the BSM (72%). In the case of COM, only 14 of the 70 categories, including waste paper, clear polyethylene terephthalate bottles, and polypropylene cups for drinking water, generated 80% of the profit and the other items should be eliminated from the list to avoid overwhelming the participants. This study found that households can earn an average of 322,000xa0Rp (23.2 USD) per year from waste reclamation. The managers of waste banks can emphasize that this amount is sufficient to by school supplies for children in campaigns promoting BSM.

Evaluation of Environmental Emissions for Optimization of Highway Improvement Programme

Improvement Programme Md. Moshiur RAHMAN Graduate Student Graduate School for International Development and Cooperation Hiroshima University 1-5-1 Kagamiyama, Higashi-Hiroshima, 739-8529 Japan E-mail: rahmanmosh72@yahoo.com