Vehicle Trajectory Recovery Based on Road Network Constraints and Graph Contrastive Learning

Location-based services and applications can provide large-scale vehicle trajectory data. However, these data are often sparse due to human factors and faulty positioning devices, making it challenging to use them in research tasks that require precision. This affects the efficiency and optimization of sustainable transportation systems. Therefore, this paper proposed a trajectory recovery model based on road network constraints and graph contrastive learning (RNCGCL). Vehicles must drive on the road and their driving processes are affected by the surrounding road network structure. Based on the motivations, bidirectional long short-term memory neural networks and an attention mechanism were used to obtain the spatiotemporal features of trajectory. Graph contrastive learning was applied to extract the local feature representation of road networks. A multi-task module was introduced to guarantee the recovered points strictly projected onto the road. Experiments showed that RNCGCL outperformed other benchmarks. It improved the F1-score by 2.81% and decreased the error by 8.62%, indicating higher accuracy and lower regression errors. Furthermore, this paper validated the effectiveness of the proposed method by case studies and downstream task performance. This study provides a robust solution for trajectory data recovery, contributing to the overall efficiency and sustainability of transportation.