Holistic Semantic Representation for Navigational Trajectory Generation

TL;DR

This paper introduces HOSER, a comprehensive semantic framework for generating realistic navigational trajectories by integrating multi-scale spatial and temporal semantics, improving performance especially in data-scarce scenarios.

Contribution

The paper proposes a novel holistic semantic representation framework that combines road, zone, point, and trajectory semantics for improved trajectory generation.

Findings

HOSER outperforms existing methods on three real-world datasets.

The model shows strong results in few-shot and zero-shot learning scenarios.

Extensive experiments validate the effectiveness of the holistic semantic approach.

Abstract

Trajectory generation has garnered significant attention from researchers in the field of spatio-temporal analysis, as it can generate substantial synthesized human mobility trajectories that enhance user privacy and alleviate data scarcity. However, existing trajectory generation methods often focus on improving trajectory generation quality from a singular perspective, lacking a comprehensive semantic understanding across various scales. Consequently, we are inspired to develop a HOlistic SEmantic Representation (HOSER) framework for navigational trajectory generation. Given an origin-and-destination (OD) pair and the starting time point of a latent trajectory, we first propose a Road Network Encoder to expand the receptive field of road- and zone-level semantics. Second, we design a Multi-Granularity Trajectory Encoder to integrate the spatio-temporal semantics of the generated trajectory at both the point and trajectory levels. Finally, we employ a Destination-Oriented Navigator to seamlessly integrate destination-oriented guidance. Extensive experiments on three real-world datasets demonstrate that HOSER outperforms state-of-the-art baselines by a significant margin. Moreover, the model's performance in few-shot learning and zero-shot learning scenarios further verifies the effectiveness of our holistic semantic representation.