Spatial–Temporal Convolutional Model for Urban Crowd Density Prediction Based on Mobile-Phone Signaling Data

Urban crowd density prediction is essential for transport demand management and public safety monitoring. Existing studies for crowd density prediction only focus on a few transport modes which do not cover all urban crowds. Moreover, most existing models rely on grid-based divisions, which cannot accommodate unevenly distributed populations. This study proposes a novel model for predicting crowd density in urban areas with mobile-phone signaling data (MPSD). MPSD contain diversified travel and activity information that is not limited to specific transport modes and are practical for activity-travel research. We introduce methods for preprocessing MPSD and extracting information on crowd density and activity choice behaviors (such as activity location, activity type, and activity duration). A novel spatial-temporal convolutional model is proposed for urban crowd density prediction. We design an attention-based feature fusion block, enabling the model to comprehensively consider historical crowd density, activity choices, and external factors (such as weather conditions and holidays). With tailored spatial-temporal convolution blocks, our proposed model successfully captures spatial-temporal information related to crowd movement in different scenes. Unlike existing grid-based models, the proposed model can predict crowd density in irregular-shaped regions. Experimental results show that our model outperforms baseline models that do not apply activity information when selecting different prediction offsets, especially for long-term predictions. The correlation between prediction error and the regularity of crowd activities is also analyzed. The subsequent parameter analysis shows that the influence of external factors on urban crowd movement varies according to activity choices and other travel-related factors like commuting distance.