CV

Research areas: Human-Centered AI · Human–Machine Interaction · Adaptive AI Assistance · Safety-Aware Multimodal Reasoning · Human–Autonomy Coordination

Education

• 2023 – 2027Ph.D. in Transportation, Korea Advanced Institute of Science and Technology (KAIST)
  Cho Chun Shik Graduate School of Mobility · Advisor: Prof. Tiantian (Nicole) Chen · Expected June 2027
• 2022 – 2023M.S. in Data-Driven Modeling, The Hong Kong University of Science and Technology (HKUST)
  Department of Physics and Mathematics
• 2018 – 2022B.E. in Traffic Engineering, Tongji University
  College of Transportation · Minor in Traffic Design, Management, and Control

Research Experience

• 2026 – present
  Visiting Ph.D. Student, JTL Urban Mobility Lab, Massachusetts Institute of Technology (MIT)
  Department of Urban Studies and Planning · Host: Prof. Jinhua Zhao · Cambridge, MA, USA

  • Investigating human responses to autonomous vehicles and their implications for interaction and coordination in mixed traffic.
• 2023 – present
  Ph.D. Student Researcher, HumanFACTS Lab, KAIST
  Cho Chun Shik Graduate School of Mobility · Daejeon, South Korea

  • Personalized AI assistance. Developed an LLM-based driver-assistance agent integrating driver profiles, traffic context, and retrieval to generate personalized multimodal warnings.
  • Human-in-the-loop evaluation (ongoing). Conducting a driving-simulator study comparing AI-generated and conventional warnings, measuring driver attention, situation awareness, and driving behavior.
  • Ethical AI evaluation. Examined LLM decision patterns in autonomous-vehicle ethical dilemmas and compared them with human moral preferences.
  • Research synthesis. Led a PRISMA-guided review of 68 studies on LLM-enabled automotive HMI and proposed the MODEL–REASON–ACT framework.

Publications

Journal Articles

• TR-C 2026Large Language Models for Enhancing Human-Machine Interaction in Autonomous Vehicles: A Comprehensive Survey Zixuan Xu, Zihao Sheng, Sikai Chen, Tiantian Chen Transportation Research Part C: Emerging Technologies, 2026 · Paper · Code
• CTR 2025MetaSSC: Enhancing 3D semantic scene completion for autonomous driving through meta-learning and long-sequence modeling Yansong Qu, Zixuan Xu, Zilin Huang, Zihao Sheng, Sikai Chen, Tiantian Chen Communications in Transportation Research, 2025 · Paper
• IEEE ITS Mag. 2025Personalizing Driver Agent Using Large Language Models for Driving Safety and Smarter Human–Machine Interactions Zixuan Xu, Tiantian Chen, Zilin Huang, Yang Xing, Sikai Chen IEEE Intelligent Transportation Systems Magazine, 2025 · Paper
• TBS 2025Where is morality on wheels? Decoding large language model (LLM)-driven decision in the ethical dilemmas of autonomous vehicles Zixuan Xu, Neha Sengar, Tiantian Chen, Hyungchul Chung, Oscar Oviedo-Trespalacios Travel Behaviour and Society, 2025 · Paper Outstanding Student Paper Award at the 28th HKSTS International Conference.

Conference Proceedings

• ITSC 2025LLM-TripPlanner: A Large-Language-Model-Based Agent for Personalized Trip Planning Yiping Liu, Hyungchul Chung, Zixuan Xu, Kitae Jang, Sikai Chen, Tiantian Chen IEEE International Conference on Intelligent Transportation Systems (ITSC), 2025 · Paper
• ITSC 2024A LLM-based Multimodal Warning System for Driver Assistance Zixuan Xu, Tiantian Chen, Sikai Chen IEEE International Conference on Intelligent Transportation Systems (ITSC), 2024 · Paper

Research Projects

• 2026 – presentModular Chiplet Structure-Based Human-Centered AI Foundation Models for Robust, Scalable Automated Driving
  Korea Institute for Advancement of Technology (KIAT) · Korea–U.S. R&D · Student Researcher
• 2026 – 2029Development of a Detachable On-Board Device for Multi-Vehicle Remote Operation and Safety Enhancement Technologies (DOVE)
  Korea Planning & Evaluation Institute of Industrial Technology (KEIT) · Korea–Czech R&D · Student Researcher
• 2024 – 2027Empowering Mobility for a Smart Aging Society: Developing and Testing of Large Language Model-Based Driver Assistance Agent
  National Research Foundation of Korea (NRF) · Lead Student Researcher
• 2024 – 2026⟨Mobility 100⟩ Sustainable Mobility in Villages: Innovative Technologies and Policies for Super-Aged Societies
  KAIST Strategic Initiative for Super-Aged Society · Lead Student Researcher

Honors & Awards

• Jul 2026Best Lightning Talk Award
  26th COTA International Conference of Transportation Professionals (CICTP 2026), Jinan, China
• Feb 2026Readers’ Choice Award
  KAIST Breakthroughs (College of Engineering Research Webzine)
• Sep 2025Outstanding Teaching Assistant Award
  KAIST Cho Chun Shik Graduate School of Mobility
• Dec 2024Outstanding Student Paper Award (Second Prize)
  28th International Conference of the Hong Kong Society for Transportation Studies (HKSTS)
• Sep 2023KAIST Prestige Scholarship for International Ph.D. Students
  Korea Advanced Institute of Science and Technology (KAIST)
• Sep 2022Entry Scholarship
  The Hong Kong University of Science and Technology (HKUST)

Talks

• Sep 2026Large Language Models for Intelligent Vehicles
  Invited industry seminar Korea Automotive Technology Institute (KATECH)
• Jul 2026Hazard-Reasoner: severity-aware traffic hazard reasoning with vision–language models
  Lightning talk 26th COTA International Conference of Transportation Professionals (CICTP 2026) · Jinan, China
  Best Lightning Talk Award
• Dec 2025Two talks: LLM-TripPlanner; LLM decision-making in ethical dilemmas of autonomous vehicles
  29th International Conference of the Hong Kong Society for Transportation Studies (HKSTS)
• Jun 2025Personalizing Driver Agent Using Large Language Models for Driving Safety and Smarter Human–Machine Interactions
  Journal presentation IEEE Intelligent Vehicles Symposium 2025 · Cluj-Napoca, Romania
• Dec 2024How does the large language model decide to save pedestrians or passengers? Evaluation of ethical dilemmas in ChatGPT-based decision-making of autonomous vehicles
  Conference presentation 28th International Conference of the Hong Kong Society for Transportation Studies (HKSTS) · Hong Kong SAR, China
  Outstanding Student Paper Award (Second Prize)
• Sep 2024A LLM-based multimodal warning system for driver assistance
  Invited session 2024 IEEE International Conference on Intelligent Transportation Systems (ITSC) · Edmonton, Canada
• Jul 2024Personalizing Driver Agent Using Large Language Models for Driving Safety and Smarter Human–Machine Interactions
  Workshop presentation Workshop on Traffic Safety Applications, Kyoto University · Kyoto, Japan

Teaching

• Spring 2025Teaching Assistant, MO.60010: Traffic Safety (graduate elective)
  Cho Chun Shik Graduate School of Mobility, KAIST

Academic Service

• Journal reviewer: Transportation Research Part A: Policy and Practice; Travel Behaviour and Society; IEEE Transactions on Vehicular Technology; IEEE Open Journal of Intelligent Transportation Systems
• Conference reviewer: IEEE Intelligent Transportation Systems Conference (ITSC); IEEE Intelligent Vehicles Symposium (IV)

Technical Skills

• Programming: Python, C#, R
• AI / ML: PyTorch, Hugging Face, LLMs and VLMs, fine-tuning (LoRA, QLoRA), RL post-training (GRPO), ms-swift, vLLM
• AI systems: LLM agents, retrieval-augmented generation (RAG), LangChain, multimodal inference
• Simulation: Unity (driving-simulator development), Autoware
• Research tools: Linux, Git, Jupyter, LaTeX