为预测运输结构调整背景下的城市群干线网络货运需求,以京津冀城市群为研究对象,首先利用灰色系统基本理论分析货运需求影响因素,并基于城市群人口、第一、二、三产业增加值、铁路营业里程、公路通车里程构建货运需求预测模型。检验结果表明,模型对货运需求总量预测的平均绝对误差为5.16%。然后,根据城市群内各地级市货运需求预测结果,将大宗货物由公路运输转为铁路运输,完成运输结构调整。接着,利用传统“四阶段法”开展城市群货运需求分布和分配预测。最后,利用实际观测站货运量数据进行预测结果校核。结果表明,货运需求预测结果分配至路网的平均绝对误差为14.56%,所建预测模型及方法可有效预测运输结构调整背景下的城市群干线网络货运需求。

In order to forecast freight demand of urban agglomeration arterial road network based on transportation structure adjustment, taking Beijing-Tianjin-Hebei urban agglomeration as a case study, firstly, the factors affecting freight demand were analyzed by using the basic theory of gray system. Then, a freight demand prediction model was constructed based on the factors, such as population, value added in three main industries, the railway and highway mileage. The test result showed that the average absolute error of model prediction is 5.16%. Secondly, the road freight transportation demand of each city within the urban agglomeration was forecasted separately, and according to this, the transportation structure was adjusted based on the "highway to railway" policy for bulk cargo. Thirdly, the freight transportation demand was distributed and assigned based on the traditional "four-stage method". Finally, the accuracy of the model prediction was tested by the actual observed data from highway observatories, and the result showed that the average absolute error of the assignment result is 14.56%. It means that the proposed method can effectively predict the freight demand of urban agglomeration based on transportation structure adjustment.