Hiroaki Nishiuchi

Spatial-Temporal Daily Frequent Trip Pattern of Public Transport Passengers Using Smart Card Data

Rebuilding the operation scheme of public transportation is a recent topic of discussion in Japan because the number of passengers is decreasing especially in rural areas. This research empirically analyzes variations in trip patterns to understand how passengers’ daily travel patterns vary temporally and spatially among one month using smart card data. The analysis reveals that the daily number of trips for the entire network does not vary significantly. However, it also reveals that daily frequent trip patters of individual passengers vary, i.e., most passengers are not traveling by a single trip pattern. This could be fundamental knowledge to discuss more detail or individual operation schemes.

Calibrating a social force based model for simulating personal mobility vehicles and pedestrian mixed traffic

Abstract Personal mobility vehicles (PMVs), such as the Segway, have recently gained remarkable popularity as an alternative transport mode for short-distance trips in indoor and outdoor settings. Before allowing them on shared sidewalks, where the pedestrian and cyclist demand is high, interactions between PMV riders and other shared space users should be properly understood. Further, the designs of shared sidewalks and implementation policies should also be evaluated. Calibrated microscopic simulation tools could facilitate such purposes. This study aims to explore the applicability of a social force based microscopic simulation model, which was originally used to simulate pedestrian movements and interactions, for Segway and pedestrian mixed traffic. The parameters of the model are calibrated with data collected through controlled experiments under different Segway–pedestrian interaction scenarios. Lateral and longitudinal avoidance distances measured from trajectory data collected in a different controlled experiment was used to validate the model for a Segway rider avoiding a pedestrian. The findings of this study suggest that, with proper calibration, the social force model can potentially be used to simulate Segway-like PMVs and pedestrian mixed traffic.

Impact analysis of reductions in tram services in rural areas in Japan using smart card data

Rural cities in Japan need to maintain public transport services because the proportion of elderly people in the population is increasing. However, measures to reduce the frequency of public transport services are under consideration in such cities because the number of passengers and the income necessary to keep services in operation are both decreasing. This study empirically analyzes the change in the number of tram passengers after the frequency of service was reduced in the study area. Especially, an analysis is applied to a survival time model using smart card data to evaluate what origin–destination pairs between tram stops (tram OD) can maintain a suitable number of passengers. The parameters estimated in the model show that a reduction in the number of trams does not directly lead to a change in the number of tram OD passengers. However, the average number of tram OD passengers and its variance are significant factors in explaining the decrease in the number of tram OD passengers. Sensitivity analysis by using the estimated model during the period of study shows that a tram OD pair that originates in a suburban area and terminates in a city center tends to have a higher probability of survival, but a tram OD pair originating from a city center tends to have a lower probability of survival. The results of this study are fundamental materials for a discussion on which tram OD pairs should be considered by public transport authorities to maintain or increase the number of passengers.

DEVELOPMENT OF A SIGNAL CONTROL SYSTEM USING MOVABLE MONITORING TOOLS

This study develops the framework of a temporary signal control system using the traffic counts from movable vehicle detectors and the vehicle trajectory data from probe vehicles equipped with Global Positioning Systems (GPS). Also it includes not only the concept of minimizing the volume of total travel time but also CO(2) emission. In order to achieve effective signal control, signal parameters should be determined in accordance with traffic flows. However, monitoring systems, which are installed on roads as a fixed infrastructure, is usually not installed for temporary use. Therefore, after a method of estimating the volume of CO(2) emission is proposed, this study develops a framework of signal control system with movable monitoring tools and validates the movable detectors by checking the accuracy of their counts. Through the validation, the paper confirms that the accuracy of the observed traffic volume is fairly good but the estimated saturation flow rate has the tendency of over-estimation.