Takayuki Morikawa

• Nagoya University

Owing to the shareability and spatial-temporal imbalance of free-floating bike-sharing (FFBS), the users may fail to pick up the bike at the desired location (i.e., the demand is truncated). Consequently, the demand partially migrates to nearby areas or is lost. Thus, the observed demand recorded in the system is not the underlying real demand. To...

Telecommuting has reached unprecedented levels in Japan, previously established due to the sudden outbreak of the COVID-19 pandemic; however, there is a lack of in-depth research on telecommuting frequency from the perspective of the post-pandemic era. Hence, this study investigated the relationship between employees’ expected levels of telecommuti...

Public transport services in mountainous areas are limited, and seniors living in such areas experience various inconveniences in their daily lives. Therefore, the planning of adequate services is crucial in improving the quality of life. Conventionally, public transport services are planned based on observed trip demands, which are referred to as...

The free-floating bike-sharing system enables users to pick up bikes from everywhere. However, the spatial-temporal imbalance of bikes becomes severer in such systems. Consequently, bikes are sometimes not available at desired location and time, and the pick-up demand of users is truncated. On demand truncation, the bike user would either give up u...

As an emerging travel mode, the modular vehicle system (MVS) is receiving increasing attention. In particular, the operators could connect multiple modular vehicles as an assembled bus in response to the temporary demand varies. Therefore, in this study, the MVS is adopted in the context of customized bus design to satisfy passengers reserved trave...

The COVID-19 pandemic and the resultant preventive measures worldwide have accelerated a change in the way millions of people work. Telework became necessary to prevent the spread of coronavirus and reduce office workers’ health risk. The change in employees’ workstyle may directly impact commuters’ travel behavior, which affects individuals’ resid...

Automated driving and the widespread use of large-scale communication infrastructure are expected to facilitate highly cooperative driving. Although considerable research has focused on developing efficient cooperative control methods for nonsignalized intersections, the effect of cooperative control for conflicting target vehicles on future traffi...

In recent years, the implementation of autonomous vehicles has been widely discussed worldwide. In particular, urban transportation demand is expected to change significantly when autonomous taxis (ATs) are introduced. Thus, planners must anticipate changes in traffic conditions and the number of users of other transport modes. Therefore, changes i...

The flexible and personalized street-hailing taxi service constitutes an indispensable component of urban mobility. However, most studies have focused only on the observed demand (pickup record) while ignoring the unmet demand. If based only on such analysis, the effectiveness of demand management policies and taxi searching strategies will be unde...

Introduction: This study explored the influence of personal attributes on subjectively-reported aggressive driving behaviors, with an emphasis on the inter-influences between subjectively-reported aggressive driving behaviors between self and other individuals. To determine this, a survey was conducted comprising participants' socio-demographic da...

The serviceability of a road network often faces challenges of traffic congestion and natural disasters which can damage the performance of many links within the network. To ensure the high performance of a road network, it is essential to identify and protect the critical links which if disrupted will cause substantial damage to the network. This...

Attitudes and perceptions expressed by respondents in questionnaire surveys play an important role in creating informed policy decisions. Under a complex environment policy, within the European Union, that is aimed at tackling urban mobility challenges, member states such as Romania have recently been transposing and assimilating Sustainable Urban...

This study aimed to examine the underlying interrelationships between traditional taxi services and online ride-hailing. To this end, demand data for these two mobility modes were collected from Xiamen Island, China, for three typical days in June 2020. By considering censoring and the potential interdependence and endogeneity of the demand variabl...

Before the final advent of Robo-taxi, careful preparations for integrating the Robo-taxi into society and understanding how travelers value the Robo-taxi against other travel modes are indispensable. To this end, a stated preference (SP) survey was conducted to understand people’s travel mode choice behavior for commuting, shopping, and hospital vi...

This study aims to measure the causal relationship between three railway projects in different regions of Nagoya city and the residential distribution of different households. Rather than assuming that a railway project has an identical impact on all the neighborhoods in the treated group, this study proposes a heterogeneous difference-in-differenc...

The paradigms of taxis and ride-hailing, the two major players in the personal mobility market, are compared systematically and empirically in a unified spatial–temporal context. Supported by real field data from Xiamen, China, this research proposes a three-fold analytical framework to compare their mobilities, including (1) the spatial distributi...

Previous studies have proven the significant causal relationship between railway investment and gentrification in some cities. However, most of them have focused on the gentry and less on the effect on other social classes. To observe how railway investment affects neighborhood change for different population types, this study investigated the inve...

The Great East Japan Earthquake in 2011 caused a lot of people unable to go home because public transportation service was extensively suspended at Tokyo metropolitan area. The same problem is concerned at Chukyo metropolitan area, due to Nankai megathrust earthquakes. This study aims to estimate the number of people who are unable to go home and t...

Introduction: This study aims to explore the influence of Big Five personality traits in combination with various socio-demographic factors and experiences of accident involvement on aberrant driving behaviors. The study also compares the effects of the level of development (i.e., developed or developing) of three countries on the personality trai...

The increasingly wide usage of smart infrastructure and location-aware terminals has helped increase the availability of trajectory data with rich spatiotemporal information. The development of data mining and analysis methods has allowed researchers to use these trajectory datasets to identify urban reality (e.g., citizens’ collective behavior) in...

The limitation of battery size for electric vehicles has driven researchers to study driving distance. Trip patterns and traveler preferences in terms of distance are affected by multiple variables. This study, using socioeconomics, weather conditions, and vehicle characteristics as covariates, compares lognormal, log-logistic, and Weibull distribu...

Demand forecast of new public transportation (PT) is essential for appropriate policymaking. In the forecasting process, the effects of social interactions on individual choices are attracting considerable attention. Traditionally, these interactions have been evaluated in the relationship between the individual’s behavior and the group’s behavior....

The aim of the study is to examine the potential effect of attitudes towards physical activity on bus utility in the context of a rural area where studies have shown that the level and opportunity for physical activity are generally low. The need to analyze attitudes remains a strong motivation for the application of integrated choice and latent va...

This study examines the effect of people's attitudes toward physical activity on their bus use intention in rural areas in Japan. We utilized the theory of planned behavior and designated three variables—attitude toward bus use, subjective norms, and perceived behavioral control—as mediators for the hypothesized effect. Analysis results showed that...

Urban congestion charging (CC) is regarded as a potentially powerful instrument aimed at changing road users’ travel behavior and achieving efficient infrastructure use. Yet, at the same time, implementing this policy is not easy. There are thoughtful barriers to the pursuit of the CC implementation. The public is skeptical about such a policy, so...

The aim of the present study was to investigate the basic cross-cultural differences in the aberrant driving behaviors of Japanese, Chinese, and Vietnamese drivers. Overall, the Vietnamese drivers reported more instances of all four types of aberrant behaviors on the road as compared to the drivers from the other two countries. On the contrary, the...

Road transportation is one of the major sources of greenhouse gas emissions. To reduce energy consumption and alleviate this environmental problem, this study aims to develop an eco-routing algorithm for navigation systems. Considering that both fuel consumption and travel time are important factors when planning a trip, the proposed routing algori...

The transit-induced residential gentrification caused by two urban rail transit lines in Nagoya, Japan is investigated individually. The difference-in-differences model, a quasi-experimental model, is used to explore the possible causal relationship between rail investments and residential gentrification. Two rail transit lines, which consist of su...

This article focuses on understanding the factors affecting the subconscious minds of urban citizens in terms of promoting clean energy and deregulation of the electricity sector. Does risk perception related to climate change and nuclear energy effect their choices? Does it differ between cities? A comparative analysis was performed for four citie...

A public transport (PT) system that is a low carbon transport option is vital for sustainable urban development. However, introducing this type of system in developing cities may be a challenge given residents’ common practice of using private vehicles, especially motorcycles, for transportation. Taking Ho Chi Minh City as an example, this study ai...

The collapse of the socialist bloc in late 1989 exposed Romania to the global economy to certain degrees, restructuring its internal economic market, as well as political and administrative structures, bringing significant changes to the structural and functional characteristics of urban areas. As the built environment and socio-economic characteri...

This paper covers a broadly used methodology used in travel behavior research aiming at determining individual and alternative-specific variables that influence the choice of the transportation mode for commuting trips. Data used in the analysis were obtained in July 2015 by means of a computer-assisted telephonic interview survey conducted in Cluj...

Dynamic shared autonomous taxi (SAT) systems are regarded as a promising means of improving travel flexibility. With no human drivers, SATs urgently require precise traffic information in order to plan accurate paths independently; in addition, on-time arrival is an essential service quality in SAT systems. In this study, taxis are assumed to be re...

This paper investigates the factors affecting drivers’ vehicle fuel consumption efficiency, which was defined as the daily average fuel consumption for a unit of driving mileage. Based on the long-term Controller Area Network (CAN) data collected from private cars during 10 months in Toyota City, Japan, we explored the relationships between drivers...

This study examined a cooperative merging control methodology for connected vehicles to optimize traffic flow without considering a traffic priority/non-priority at intersections. A cellular automata microsimulation was constructed to examine the methodology. It was used for simulating the traffic condition and for predicting a future conflict betw...

This paper examines choice behaviors pertaining to the time at which users of plug-in hybrid electric vehicle with 24 km electric range charge their vehicles after arriving at home under a dynamic electricity pricing scheme. The following mutually exclusive alternatives are presented: no charging, charging immediately after arriving at home, chargi...

Shared autonomous taxi systems (SATS) are being regarded as a promising means of improving travel flexibility. Each shared autonomous taxi (SAT) requires very precise traffic information to independently and accurately select its route. In this study, taxis were replaced with ride-sharing autonomous vehicles, and the potential benefits of utilizing...

This paper focuses on understanding the difference between East and West Japan with respect to citizens’ subjective views on renewable energy. A comparative analysis was performed for cities in the east and west because renewable energy is a natural resource unique to each location and suitable for a distributed energy network operated under the au...

As an emerging Eastern European country, Romania has exhibited continuous economic growth since the change in the political system in 1989. This has led to that gave rise to increased car ownership and extensive car usage in the country as well as, leading to rapid and uncontrolled land usage and urban sprawl. This study aims to determine individua...

Based on stated preference (SP) data collected in Ho Chi Minh City, this paper applied a latent class (LC) - standard ordered response model (SORM) to explore attitude of respondents towards Park-and-Ride (P&R) and Transportation-Eco-Point (TEP) policies. The LC model assigned the respondents into "altruistic" and "selfish" classes. Then, the SORM...

As an emerging Eastern European country, Romania has demonstrated continuous economic development since the change in its political system in 1989. This has led to increased car ownership and extensive car usage in the country as well as rapid and uncontrolled land usage and expansion of urban areas. The proposed study aims at determining individua...

The shared autonomous taxis system (SATS) has been regarded as a promising traffic mode for improving travel flexibility and reducing travel costs. This study aims to examine the potential benefits of replacing all taxis with ride-sharing autonomous vehicles (AVs). Specifically, two sharing strategies are discussed: nondetour sharing, in which a su...

This study attempts to investigate motivations for individual modal shifts of motorcycle and car users for commuting trips in the context of new public transport projects in Ho Chi Minh City. We designed a survey to obtain information on five types of potential motivations, including service quality, social interaction, psychological determinants,...

This paper concentrates explicitly on examining the structural and functional transformations occurring within the metropolitan area of Bucharest, resulting from sustained economic growth during the past quarter century, by conducting a time analysis, spanning the entire period since the fall of the communist regime in late 1989. Cities in develope...

With the high older-related accident ratio and increasing population aging problem, understanding older drivers' driving behaviors has become more and more important for building and improving transportation system. This paper examines older driver's driving behavior which includes road selection, left/right turn and driving speed. A two-month expe...

Travel time reliability has attracted considerable interest in the field of route choice modelling. Knowing how individuals choose paths with uncertain travel times is fundamental to advancing our understanding of route choice behaviour and thus driving the development of route guidance systems. In general, existing navigation systems provide the s...

Recently, the number of ambulance dispatches, arrival time to the accident site and the travel time to health facilities has increased due to aging. For building a safe and reassuring community, it is indispensable to respond quickly to emergency medical care, and there is an urgent need to improvement of road networks and efficiency of emergency f...

This study aims to determine an eco-friendly path that results in minimum CO2 emissions while satisfying a specified budget for travel time. First, an aggregated CO2 emission model for light-duty cars is developed in a link-based level using a support vector machine. Second, a heuristic k-shortest path algorithm is proposed to solve the constrained...

This paper presents an integrated analytical framework to highlight environment benefit gained from policies aiming at minimizing the impact of private transportation modes in motorcycle dependent cities. Models integrated in this framework include mode/brand choices, usages of motorcycles and cars, and an international vehicle emission (IVE). The...

This study investigates the effects of the range of a battery electric vehicle (EV) by using questionnaire data. The concern about battery depletion changes according to charging station deployment. Firstly, the methodology for deriving the probabilistic distribution of the daily travel distance is developed, which enables us to analyze people’s to...

Understanding people’s activities and travel behaviors has gained attention in service research field as well as in transportation research field. Recently, there are a lot of studies utilizing GPS (Global Positioning System) trajectory data to analyze travel behaviors after identifying each trip. Although transportation service level (e.g., travel...

The structural and functional characteristics of an urban area influences people’s lives and travel behavior for a long period of time. Little has been known about the interdependencies between life stages of an individual in the context of residential location and travel behavior. Evolution patterns in land-use and transport in Romania’s urban are...

With the government planning a congestion charging (CC) scheme for Jakarta, public support is regarded as a prerequisite for its implementation. Politicians typically see CC reform as a controversial policy if there is no public support. Yet a CC plan is currently under active development and remains under consideration as a way to mitigate the acu...

The ability to accurately predict the energy consumption of electric vehicles (EVs) is important for alleviating the range anxiety of drivers and is a critical foundation for the spatial planning, operation and management of charging infrastructures. Based on the GPS observations of 68. EVs in Aichi Prefecture, Japan, an energy consumption model is...

Autonomous driving has become a popular topic in both industry and academia. Lane-changing is a vital component of autonomous driving behavior in arterial road traffic. Much research has been carried out to investigate discretionary lane changes for autonomous vehicles. However, very little research has been conducted on assisting autonomous vehicl...

A number of discrete choice models, including a multinomial logit model (MNL), a nested logit model (NL), and a latent choice set model (LCS), are applied to the representation of gap acceptance by merging vehicles (MVs) on urban expressways and their results are compared. The results show that all models give consistent signs to the estimated para...

This paper investigates socio-demographic characteristics in the origin and terminal vertices of the time-space prism, by using the stochastic frontier method for morning and evening full time workers in the metropolitan area of Cluj-Napoca, Romania. Observed trip starting and ending times are used as dependent variables, while trip distance and ti...

This paper presents an empirical study on vehicle type choice, usage, and CO2 emissions in Ho Chi Minh City, using data of 1585 participants in a 2014 survey. A joint discrete-continuous model based on the copula approach is used to overcome selectivity bias in the data and to address the relationship between vehicle type choice (a discrete outcome...

This study aims to investigate the effects of electric vehicle's driving range on buying motivation. In particular, the authors investigate how the deployment of charging facility affects on preferred driving range of electric vehicle. In addition, after developing the method to derive the statistical distribution of daily driving range, authors in...

Road pricing (RP) is currently under development as a way to mitigate the acute traffic congestion in Jakarta. The RP has been recognized as a powerful tool in delivering efficient road use. Despite of a well-established rationale that tackled congestion, RP policy faces lack of public support and is seen rather controversial due to charge required...

Comprehensive stated choice (SC) experiments were conducted in Jakarta, Indonesia, and Nagoya, Japan, where proposals for congestion charges have been introduced and remain under consideration as a way to reduce acute car dependence, particularly in Jakarta. Causal paths among psychological determinants and their strengths are measured and analyzed...

Parking Deposit System (PDS) is proposed to improve public acceptance of road pricing (RP), which can reduce effectively traffic congestion and air pollution. This study examines the characteristics of PDS and conventional cordon-based RP in terms of efficiency and equity. In order to evaluate income regressive effects as equity, we develop a multi...

In this research, a Bayesian network (BN) approach is proposed to model the car use behavior of drivers by time of day and to analyze its relationship with driver and car characteristics. The proposed BN model can be categorized as a tree-augmented naive (TAN) Bayesian network. A latent class variable is included in this model to describe the unobs...

This study explores how battery electric vehicle users choose where to fast-charge their vehicles from a set of charging stations, as well as the distance by which they are generally willing to detour for fast-charging. The focus is on fast-charging events during trips that include just one fast-charge between origin and destination in Kanagawa Pre...

An increasing number of researchers have shown an interest in enhancing discrete choice models by incorporating psychological and behavioral factors. The main objective of this paper is to explore the effect of observed and unobserved heterogeneity on route choice. The mixed logit framework is applied to consider the heterogeneity. In contrast with...

This paper examines older driver’s automotive trip (abbreviation: trip) characteristics which include trip frequency, trip length, destination distribution, and non-home-based (NHB) trips. A two-month experiment of 108 participants was carried out to collect GPS tracking data in Aichi Prefecture, Japan. To identify the effect of living area, a comp...

This study aims to find an experientially reliable path considering travel time uncertainty and driving experience of local probe vehicle drivers. Accordingly, a two-stage route-finding procedure is proposed. First, a set of candidate paths is built by using the hyperpath algorithm, where the choice probability is assigned to each link with uncerta...

Ever since global positioning system (GPS) modules have been attached to smart phones, much research has focused on how to obtain personal trip (PT) information from them. One of the challenges is identifying activity type (or inferring the purpose of the trip) from these continuous GPS data. This paper focuses on obtaining the type of activity usi...

Transportation fleets and on-road driving characteristics have known as significant factors on traffic emissions, additionally important parameters in International Vehicle Emission (IVE) model for emission inventories. Using data collected in Ho Chi Minh City, this paper analyzes characteristics of these parameters and it mainly focuses on passeng...

This study aims to explore the trip fuel consumption from a large-scale dataset. To better understand how the multiple variables (e.g., average travel speed, trip distance) influence the trip fuel consumption, we propose the support vector machine (SVM) to learn the relationship between the trip fuel consumption and the corresponding factors. A lar...

Parking management has attracted attention as an effective transportation policy. Although many studies analyzing parking lot choice behaviors have been conducted, most of them utilized data gathered by one-shot questionnaire surveys. Currently, in Japan, it is possible to easily observe parking lot choice behaviors over long time periods since onl...

This study explores the location of bicycle stations and the use of a community cycle system (CCS) in Nagoya city, Japan, based on survey data collected through a social experiment using 300 bicycles and 30 bicycle stations. The service area was located within the central area of Nagoya and covered 1.5 km from north to south and 2.5 km from east to...

The scope of the study is to bring contributions to the understanding the changes within the transportation system as result of economic development in post-socialist countries in the last 25 years. Given that car ownership is important to transport and land-use planning and its relationship with energy consumption, the environment and health, the...

This paper examines the influences of environmental consciousness and attitudes to transportation on electric vehicle purchase intentions. A multiple-indicators?multiple-causes model and a latent-class nested logit model with two segments were estimated using data obtained through a web-based questionnaire survey in the Chukyo Area of Japan. Result...

The vehicle fuel consumption frontier (VFCF) is the unobserved maximum amount of fuel that an individual private car user is willing to consume for driving. This study incorporated interindividual and intraindividual variations into the modeling of VFCF. Long-term controller area network data collected from private cars during 10 months in Toyota C...

The aim of this paper is to examine the evolution patterns in land-use and transport that have been occurring during the past 25 years in Bucharest, Romania, against current demographic trends within the city. We have conducted this exercise in order to assess the adequacy of current policies aimed at promoting compact urban growth, engendering an...

The identification of activity locations in continuous GPS trajectories is an essential preliminary step in obtaining person trip data and for activity-based transportation demand forecasting. In this research, a two-step methodology for identifying activity stop locations is proposed. In the first step, an improved density-based spatial clustering...

This paper aims to examine choice behavior in respect of the time at which battery electric vehicle users charge their vehicles. The focus is on normal charging after the last trip of the day, and the alternatives presented are no charging, charging immediately after arrival, nighttime charging, and charging at other times. A mixed logit model with...

The aim of this paper is to investigate the intentions of Jakarta citizens with respect to the electronic road pricing (ERP) reform proposed by the city government. Utilizing data from a stated preference survey conducted in 2013, we construct six variables representing latent psychological motivations (appropriateness of ERP adoption; recognition...

The standard ordered response model (SORM) is a common disaggregate approach with ordered outcomes in which the effects of various exogenous attributes are assumed constant across ordinal choices. In this study, an innovative latent class based generalized ordered response model (LC-GORM) is formulated and used to assess the effects of various fact...

This study aims to explore how factors including charging infrastructure and battery technology associate the way people currently charge their battery electric vehicles, as well as to explore whether good use of battery capacity can be encouraged. Using a stochastic frontier model applied to panel data obtained in a field trial on battery electric...

Among driver behaviors at merging sections, gap acceptance is regarded as the most important ones. Although, many studies have been carried out to investigate the gap acceptance of merging vehicles (MVs), various influencing factors such as geometries and traffic conditions have not been thoroughly considered. This paper tries to close this gap by...

In many cities, taxis equipped with global positioning system (GPS) devices are used as probe vehicles. However, there are cases when the data from such taxis are not suitable for use as traffic information because of long data polling intervals. There are also developing countries in which taxis are not equipped with GPS devices. In such cases, a...

This paper discusses how to take into account en-route choices in utility-based route choice modelling. A path observation through a network is divided into a sequence of route choices and decision making choices at decision nodes. A driver's dynamic taste for different routes at different decision nodes is described by a mixed-logit specification....

This paper incorporates both interindividual variation and intraindividual variation into the modeling of car usage time frontiers (CUTFs). A CUTF is defined as the unobserved maximum amount of time that an individual private car user is willing to spend driving and is derived from the concept of a travel time budget. Long-term GPS data collected f...