Valuing Time in Silicon: Can Large Language Model Replicate Human Value of Travel Time

As a key advancement in artificial intelligence, large language models (LLMs) are set to transform transportation systems. While LLMs offer the potential to simulate human travelers in future mixed-autonomy transportation systems, their behavioral fidelity in complex scenarios remains largely unconfirmed by existing research. This study addresses this gap by conducting a comprehensive analysis of the value of travel time (VOT) of a popular LLM, GPT-4o. We employ a full factorial experimental design to systematically examine the LLM's sensitivity to various transportation contexts, including the choice setting, travel purpose, income, and socio-demographic factors. Our results reveal a high degree of behavioral similarity between the LLM and humans. The LLM exhibits an aggregate VOT similar to that of humans, and demonstrates human-like sensitivity to travel purpose, income, and the time-cost trade-off ratios of the alternatives. Furthermore, the behavioral patterns of LLM are remarkably consistent across varied contexts. However, we also find that the LLM's context sensitivity is less pronounced than that observed in humans. Overall, this study provides a foundational benchmark for the future development of LLMs as proxies for human travelers, demonstrating their value and robustness while highlighting that their blunted contextual sensitivity requires careful consideration.