Title: MoveFM-R: Advancing Mobility Foundation Models via Language-driven Semantic Reasoning
Primary area: foundation or frontier models, including LLMs
Keywords: Modality Alignment, Mobility Generation, Mobility Prediction

Abstract: Mobility Foundation Models (MFMs)  have advanced the modeling of human movement patterns, yet they face a ceiling due to limitations in data scale and semantic understanding. While Large Language Models (LLMs) offer powerful semantic reasoning, they lack the innate understanding of spatio-temporal statistics required for generating physically plausible mobility trajectories. To address these gaps, we propose MoveFM-R, a novel framework that unlocks the full potential of mobility foundation models by leveraging language-driven semantic reasoning capabilities. It tackles two key challenges: the vocabulary mismatch between continuous geographic coordinates and discrete language tokens, and the representation gap between the latent vectors of MFMs and the semantic world of LLMs.
MoveFM-R is built on three core innovations: a semantically enhanced location encoding to bridge the geography-language gap, a progressive curriculum to align the LLM's reasoning with mobility patterns, and an interactive self-reflection mechanism for conditional trajectory generation.
Extensive experiments demonstrate that MoveFM-R significantly outperforms existing MFM-based and LLM-based baselines. It also shows robust generalization in zero-shot settings and excels at generating realistic trajectories from natural language instructions. By synthesizing the statistical power of MFMs with the deep semantic understanding of LLMs, MoveFM-R pioneers a new paradigm that enables a more comprehensive, interpretable, and powerful modeling of human mobility.
The implementation of MoveFM-R is available online at \url{https://anonymous.4open.science/r/MoveFM-R-CDE7/}.

TL;DR: We introduce MoveFM-R, which unlocks the full potential of mobility foundation models with the semantic reasoning of large language models.