Publications (WoS)

@article{nokey,

title = {Measuring the impact of built environment factors on station-level contributions to link-level crowding using a novel crowding contribution index},

author = {Blessy David Xavier and Varun Varghese and Makoto Chikaraishi and Akimasa Fujiwara},

url = {https://www.nature.com/articles/s41598-025-27483-y},

doi = {https://doi.org/10.1038/s41598-025-27483-y},

issn = {2045-2322},

year  = {2025},

date = {2025-12-10},

urldate = {2025-12-10},

journal = {Scientific Reports},

volume = {15},

number = {43535},

abstract = {Metro crowding undermines passenger comfort, operational efficiency and network reliability. While prior research has examined station-level and system-wide crowding, little attention has been given to quantifying how individual stations contribute to link-level overcrowding. This study addresses this gap by introducing the Crowding Contribution Index (CCI), a metric that quantifies the extent to which destination stations drive overcapacity flows on preceding links. The CCI is computed via a structured framework integrating Automated Fare Collection (AFC) and GTFS link-network data. Applied to over 80 million trips across 237 Delhi Metro stations, 142 200 hourly CCI values reveal that 46.35% of station-hours exceed capacity, with highest contributions clustered in specific stations. A Type II Tobit model assesses built-environment (BE) variables, showing that POI and intersection densities increase contributions, while POI entropy reduces them, underscoring land-use diversity’s role. Random Forest and XGBoost models corroborate these findings, ranking BE variables as the strongest CCI predictors. These insights emphasise the need for integrated land-use and transport strategies. The CCI framework offers operators a scalable tool for real-time service adjustments, such as targeted short-turns and dynamic fleet deployment, and guides planners toward sustainable, integrated land-use planning, making it especially valuable for rapidly urbanising, data-constrained cities.},

keywords = {Transit-oriented development, Transportation},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Understanding Human–Computer Interaction with Shared Autonomous Shuttles through Twin Experience: A Hybrid Choice Modeling Approach},

author = {Son Van Pham and Akimasa Fujiwara and Makoto Chikaraishi and Son Anh Le and Nang Ho Xuan},

url = {https://www.tandfonline.com/doi/full/10.1080/10447318.2025.2591777},

doi = {https://doi.org/10.1080/10447318.2025.2591777},

issn = {1044-7318},

year  = {2025},

date = {2025-11-28},

urldate = {2025-11-28},

journal = {International Journal of Human–Computer Interaction},

abstract = {This study investigates future mobility with the introduction of shared autonomous shuttles (SASs), focusing on how human–computer interaction (HCI) influences travel decisions, using a twin experience survey approach. Data were collected in January 2023 from 1376 participants, based on experimental scenarios with Level 4 SASs in Hanoi. A hybrid choice model was developed to examine the effects of HCI, travel attributes, latent psychological factors, and socio-demographic characteristics. The study suggests that SAS Economy could serve as an affordable and scalable complementation for short trips, greater satisfaction with SAS Economy over ride-hailing, and higher trust compared to motorbikes. The findings also highlight the need for transparent and adaptive service designs to foster user trust, and for policymakers to integrate SASs into broader Mobility as a Service strategies. Overall, this study supports a mobility-oriented development adaptable to diverse urban settings, contributing to carbon neutrality and the development of healthier cities through a smart mobility platform.},

keywords = {Mobility as a Service, Shared Autonomous Electric Mobility, Transportation},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Transformative impacts of shared autonomous vehicles for first-last-mile mobility: A cyber-physical experiment concept},

author = {Son Van Pham and Hyewon Namgung and Fujiwara Akimasa and Makoto Chikaraishi and Thi Anh Hong Nguyen and Canh Do and Anh Son Le and Xuan Nang Ho},

url = {https://www.sciencedirect.com/science/article/pii/S2590198225003197},

doi = {https://doi.org/10.1016/j.trip.2025.101640},

issn = {2590-1982},

year  = {2025},

date = {2025-10-01},

urldate = {2025-10-01},

journal = {Transportation Research Interdisciplinary Perspectives},

volume = {34},

number = {101640},

abstract = {The study introduced the cyber-physical experiment concept (CPEC) to comprehensively investigate and demonstrate new mobility services, specifically focusing on the impact of shared autonomous vehicles (SAVs) on the change of mode choice behavior. By synergistically combining cyber and physical experiments, the integrated experiment approach provided insights into user’s shifts to SAVs as a first-last-mile (FLM) mode choices in Hanoi. The study involved 1030 respondents in the cyber experiments and 346 respondents in the physical experiments with SAVs, respectively. Utilizing a panel mixed logit (PMXL) model and difference-in-differences (DID) analysis, the findings revealed that cyber and physical experiments significantly influenced behavior change following the introduction of SAVs, which were previously unavailable. Both the cyber and physical experiments improved overall preferences for SAVs. However, differences emerged between the groups: participants exposed only to cyber experiments showed higher travel mode transfer rates compared to those who participated in the physical experiments. From a policy perspective, this study advocates for an integrated system to address FLM challenges, particularly in the context of banning motorbikes in inner-city areas and positioning SAVs as viable alternatives. These findings underscore the theoretical contributions and practical implications of CPEC in integrating SAVs into public transportation systems to enhance FLM mobility.},

keywords = {Mobility as a Service, Shared Autonomous Electric Mobility, Transportation},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Mobility experiment twin for analyzing travel behavior decisions employing shared electric autonomous vehicles},

author = {Son Van Pham and Akimasa Fujiwara and Makoto Chikaraishi and Anh Son Le and Nang Ho Xuan},

url = {https://www.tandfonline.com/doi/full/10.1080/19427867.2025.2525290},

doi = {https://doi.org/10.1080/19427867.2025.2525290},

issn = {1942-7867},

year  = {2025},

date = {2025-07-08},

urldate = {2025-07-08},

journal = {Transportation Letters: The International Journal of Transportation Research},

abstract = {The introduction of new mobility services (NMS) strongly depends on the public acceptance. Acceptance is evaluated by allowing users to experience these solutions before their widespread implementation. However, there is limited research on establishing robust frameworks for analyzing travel behavior decisions across the stages and environmental contexts of implementation. This study proposes the mobility experiment twin (MEXT) framework, which integrates cyber and physical experiments using a five-step approach. We introduced shared autonomous electric vehicles (SAEVs) as first-last-mile (FLM) urban mobility vehicles in Hanoi. Utilizing randomized controlled trials with cyber and physical groups to estimate the impact of MEXT. The users preferred SAEVs, willingly accepting longer travel times and higher costs, while young people were more inclined to adopt SAEVs with economic costs. Future works must consider more representative experimental locations and develop a theoretical model that better reflects the current SAEV situation in developing societies.},

keywords = {Behavior, Difference-in-differences (DiD), Mobility as a Service, Shared Autonomous Electric Mobility, Transportation},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Investigating influential factors on pick-up/drop-off location choices for school bus services from parents' perspective: A case study in Hanoi, Vietnam},

author = {Hung N.V Do and Akimasa Fujiwara and Thi Anh Hong Nguyen and Canh Do},

url = {https://www.sciencedirect.com/science/article/pii/S218555602500001X},

doi = {https://doi.org/10.1016/j.eastsj.2025.100157},

issn = {2185-5560},

year  = {2025},

date = {2025-02-19},

urldate = {2025-02-19},

journal = {Asian Transport Studies},

volume = {11},

abstract = {This study examines factors influencing parents' choices of relocating pick-up/drop-off (PUDO) points of school bus services for six schools in Hanoi. An online survey, in which parents were asked to choose a PUDO point after viewing a video showing current traffic conditions, was administered in November 2022. They were then exposed to a proposal for a new PUDO location that enhanced the school walking environment. The results suggested that parents favor further PUDO locations, enabling their children to participate in longer walks to school and increase their physical activity. However, those observing traffic accidents near school gate areas expressed negative attitudes toward the proposed change. Moreover, the study found no significant decrease in transportation costs setting up PUDO points at a greater distance. Nevertheless, encouraging physical activity and improving students' health could be a policy instrument for decision-makers to set up a designated distant PUDO location in the context of developing Asian cities.},

keywords = {Behavior, Transportation},

pubstate = {published},

tppubtype = {article}

}

@article{Namgung2023,

title = {Small and medium-sized taxi firm operators' stated choices of future business models: A case study in Japan based on hybrid choice model with panel effects},

author = {Hyewon Namgung and Akimasa Fujiwara and Jenny Yamamoto and Junyi Zhang},

doi = {10.1016/j.retrec.2023.101341},

issn = {0739-8859},

year  = {2023},

date = {2023-11-00},

journal = {Research in Transportation Economics},

volume = {101},

publisher = {Elsevier BV},

keywords = {Economics, Mobility as a Service, Transportation},

pubstate = {published},

tppubtype = {article}

}

@article{Namgung2023c,

title = {Influence of real and video-based experiences on stated acceptance of connected public transportation and autonomous vehicles in a transit mall: A hybrid choice modeling approach},

author = {Hyewon Namgung and Makoto Chikaraishi and Akimasa Fujiwara},

doi = {10.1016/j.tra.2023.103695},

issn = {0965-8564},

year  = {2023},

date = {2023-07-00},

journal = {Transportation Research Part A: Policy and Practice},

volume = {173},

publisher = {Elsevier BV},

keywords = {Aerospace Engineering, Business, Civil and Structural Engineering, Management and Accounting (miscellaneous), Management Science and Operations Research, Transportation},

pubstate = {published},

tppubtype = {article}

}