Traffic forecasting has recently attracted increasing interest due to the
popularity of online navigation services, ridesharing and smart city projects.
Owing to the non-stationary nature of road traffic, forecasting accuracy is
fundamentally limited by the lack of contextual information. To address this
issue, we propose the Hybrid Spatio-Temporal Graph Convolutional Network
(H-STGCN), which is able to "deduce" future travel time by exploiting the data
of upcoming traffic volume. Specifically, we propose an algorithm to acquire
the upcoming traffic volume from an online navigation engine. Taking advantage
of the piecewise-linear flow-density relationship, a novel transformer
structure converts the upcoming volume into its equivalent in travel time. We
combine this signal with the commonly-utilized travel-time signal, and then
apply graph convolution to capture the spatial dependency. Particularly, we
construct a compound adjacency matrix which reflects the innate traffic
proximity. We conduct extensive experiments on real-world datasets. The results
show that H-STGCN remarkably outperforms state-of-the-art methods in various
metrics, especially for the prediction of non-recurring congestion.

提出一种混合时空图卷积网络 (H-STGCN) 用于交通预测，利用在线导航引擎获取即将到来的流量数据，并结合与时间相关的交通流量信息进行空间依赖的图卷积计算，实现对交通状况的预测。在现实数据上的实验表明，相比于现有方法，H-STGCN 在各种指标上均表现出色，尤其是对于非经常发生的拥堵的预测。