  Predicting commuting flows based on infrastructure and land-use information
is critical for urban planning and public policy development. However, it is a
challenging task given the complex patterns of commuting flows. Conventional
models, such as gravity model, are mainly derived from physics principles and
limited by their predictive power in real-world scenarios where many factors
need to be considered. Meanwhile, most existing machine learning-based methods
ignore the spatial correlations and fail to model the influence of nearby
regions. To address these issues, we propose Geo-contextual Multitask Embedding
Learner (GMEL), a model that captures the spatial correlations from geographic
contextual information for commuting flow prediction. Specifically, we first
construct a geo-adjacency network containing the geographic contextual
information. Then, an attention mechanism is proposed based on the framework of
graph attention network (GAT) to capture the spatial correlations and encode
geographic contextual information to embedding space. Two separate GATs are
used to model supply and demand characteristics. A multitask learning framework
is used to introduce stronger restrictions and enhance the effectiveness of the
embedding representation. Finally, a gradient boosting machine is trained based
on the learned embeddings to predict commuting flows. We evaluate our model
using real-world datasets from New York City and the experimental results
demonstrate the effectiveness of our proposal against the state of the art.
