Tetsuo Yai

Multinomial probit with structured covariance for route choice behavior

We propose another version of the multinomial probit model with a structured covariance matrix to represent any overlapped relation between route alternatives. The fundamental ideas of the model were presented in Yai et al. (1993) and Yai and Iwakura (1994). The assumptions introduced in the model may be more realistic for route choice behaviors on a dense network than the strict assumption of the independent alternative property of the multinomial logit model. As the nested logit model assumes an identical dispersion parameter between two modeling levels for all trip makers, the model has difficulty in expressing individual choice-tree structures. To improve the applicability of the multinomial probit model to route choice behaviors, we introduce a function which represents an overlapped relation between pairs of alternatives and propose a multinomial probit model in which the structured covariance matrix uses the function in order to consider the individual choice-tree structures in the matrix and the estimatability of the new alternatives covariances. After examining the applicability of the multinomial probit model using empirical route choice data in a Tokyo metropolitan region, we also propose a method for evaluating consumer benefits on complicated networks based on the multinomial probit model.

ANALYSIS OF PEDESTRIAN BEHAVIOR AND PLANNING GUIDELINES WITH MIXED TRAFFIC FOR NARROW URBAN STREETS

The aim of this study was to examine pedestrian behavior and suggest guidelines for analyzing pedestrian traffic flow in narrow urban streets with mixed traffic. For the analysis of pedestrian behavior, 15 streets around an urban railway station in Tokyo were surveyed, and several parameters were obtained, such as pedestrian paths around stationary obstacles; share of pedestrians using the sidewalk as a factor of street environment and traffic conditions; and influence distance of and for bicycles and cars. With respect to planning guidelines, the authors have simultaneously defined a new index of time-space occupancy (Qt-si) of traffic modes in mixed-traffic conditions that considers the occupancy of time and space in the time-space diagram. Also, a new concept for level-of-service standards has been suggested for mixed-traffic conditions that employs the concept of time-space occupancy of each mode and hindrance/conflict between modes.

Incorporating choice dynamics in models of consumer behavior

This paper presents a framework for organizing and discussing factors influencing consumer choice dynamics, how these factors may be incorporated into models of buyer behavior and problems that may arise in estimating such models. The paper identifies research issues and delineates possible approaches.

Development of the Driving Simulation System MOVIC-T4 and Its Validation Using Field Driving Data

Abstract Underground urban expressways are a possibility for solving many existing transportation-related problems, such as traffic congestion in high density areas and the division of neighborhoods due to elevated roadways. However, they may also pose high risks regarding traffic safety. Therefore, it is important for a pre-analysis of traffic safety to be made. This paper describes recent efforts to develop a driving simulation system, MOVIC-T4, for traffic safety analysis of underground urban expressways. In order to develop a small portable simulator, a small-sized motion-base with two-degrees-of-freedom is used to duplicate acceleration cueing together with a head-mounted-display (HMD) for the visual system. An overview of this system is given and the reliability of driving data obtained from the experiments using MOVIC-T4 is discussed through a validation study using field driving data. The results of validation indicate that the perceived speed, distance headway, and physiological data in the simulator show the almost same trend as that in the real world, but larger decelerations tend to be produced in the simulator.

Analysis of Travel Time Saving Benefit by Understanding Individual Needs and Value of Activity Time: Case Study of Tokyo and Jakarta

Quantification of the value of time (VOT) is important for measurement of the benefit of transportation projects in terms of travel time savings. In Japan, VOT is considered higher on weekends than on weekdays because on the weekend people have limited time to allocate to discretionary activities that are not normally done on weekdays, such as family care-related activities. In Indonesia, a culturally diverse country, providers and users seem to have different perceptions of VOT. A method of analyzing the value of activity time is presented. It argues that the benefit of travel time saving should be evaluated in more detail on weekends by considering the value of discretionary activities to explain these phenomena theoretically. Activity diary surveys were conducted in Tokyo, Japan, and Jakarta, Indonesia, to verify the influence of psychological needs on peoples holiday activities. Finally, a time allocation model that uses the revealed preference data and a marginal activity choice model that uses stated preference data are proposed to calculate the value of activity time. The theories underpinning these models are Maslows psychological needs, consumer theory in economics, and a discrete choice model. The empirical results show that an individuals priority of needs influences time allocation. In particular, the results show that in Tokyo, spending time with family on weekends is more valuable than other types of activities, while in Indonesia the value of spending time with family exceeds that of work time even on weekdays.

Time Allocation Modeling for Weekend Travel in Tokyo, Using Combined Utility Maximization and Activity Choice Approaches

Travel time saving benefit is conventionally expressed as a function of wages due to increase in production time. In Japan, value of time saving is considered higher during weekends than on weekdays. The primary reason for this is that people have limited time in the weekend to allocate for activities that are not normally done on a weekday, in particular, recreational activities with family. Explaining the higher value of weekend time saving with the conventional logic of increased production time is rather difficult. So this research proposes a new method that incorporates individual life style priority to explain the phenomenon. The objective of this research is to develop a weekend time allocation model using revealed preference (RP) method with weekend time allocation data and stated preference (SP) method with individual activity extension choice data The underpinning theories are the psychological theory of needs from Maslow (1970), the utility maximization of consumer theory, and discrete choice models. The resulting model is a combination of two approaches: the utility maximization (using RP data) and activity choice by marginal utility (using SP data).

Disaggregate behavioural models and their applications in Japan

Abstract This paper focused on current advances in disaggregate studies in Japan. More than 120 materials on discrete choice modelling have already been discussed, mainly at domestic annual meetings, and nearly 70 papers related to the modelling have been published. This paper includes the following sections: (1) summarizing applications of disaggregate behavioural models, (2) briefly exploring new models and methods in Japan, and (3) presenting practical uses of the models in transportation planning fields. In conclusion, the research activities in individual choice modelling are summarized as follows: (1) active research works have been carried out to improve the practicability, (2) disaggregate approaches involve an ordinary statistical method such as a regression analysis, and (3) the models have been practically applied in transportation planning fields.

Passenger Satisfaction and Mental Adaptation under Adverse Conditions: Case Study in Manila

Public transportation systems in several developing cities face congestion, air pollution, and safety problems, yet many passengers use them regularly. This study examines the structure of passenger satisfaction and the role of mental adaptation under such conditions. Metro Manila MRT-3 was analyzed as a case study. The actual and perceived conditions at the MRT-3 were assessed using surveys. Results of the waiting time and PM2.5 monitoring surveys revealed that passengers queue for 30 minutes, on average, while being exposed to unsafe levels of PM2.5. The questionnaire survey results show some discrepancies between actual and perceived values, suggesting a perception gap. Passenger satisfaction in MRT-3 was then modeled using ordered logit, with actual and perceived conditions (waiting time, in-vehicle time, fare levels, risk perception, and air quality perception) as significant explanatory variables. Mental adaptation was found to moderate passenger satisfaction, which may explain why some passengers are satisfied despite MRT-3’s shortcomings.

Analysis of Delay Caused by Midblock Jeepney Stops with Use of Simulation

Public transit enjoys an almost 80% share of trips in Metro Manila, and the most widely used is the paratransit vehicle called the jeepney. These 18- to 22-seat vehicles, which evolved from American army service jeeps left after World War II, provide inexpensive and convenient door-to-door service but cause disruptions in traffic flow because of aggressive and problematic driving behavior, particularly when stopping to pick up or unload passengers. Other vehicles are observed to experience delays, especially in the vicinity of midblock jeepney stops with high passenger demand. An overview of work done in building and validating a traffic microsimulation program focuses on modeling the distinctive stopping behavior of jeepneys that considers both transit vehicle and passenger agents. Propensity for nonobservance of lanes and aggressive lateral movements of general traffic are considered in the model. There is also a discussion of the result of simulation experiments that used the developed simulation model called JSTOPSIM and are designed to analyze trends on average vehicle delay experienced by through vehicles as passenger demand and volume of transit and non-public transit vehicles vary. The capability to quantify objectively delays attributable to jeepney stops is important in advocating policies to improve design and operation for the improvement of the public transit system as a whole.

Intercity Transport Policy and Planning System: International Comparison Between the EU, USA, China and Japan

It has been pointed out in Sect. 1.1.2 that the share of intercity transport of total passenger-kilometres is estimated to be more than 40 % and will probably increase substantially in the future. In freight transport, the share of intercity transport is much higher and can account for more than 80 % of the total tonne-kilometres in industrialised countries. This underlines—in spite of the statistical difficulties for international comparisons—that intercity transport is a highly relevant segment of transport when it comes to analysing the responsibility of the transport sector to global warming and the potential for mitigation.