交通发生吸引量预测是交通规划四阶段的首要步骤,其预测结果是城市规划布局及交通设施建设发展的重要依据.为了提高交通发生量预测准确性,利用K-means聚类分析对交通小区进行分组;对同组内样本小区各项土地利用及人口就业指标进行主成分分析,通过计算主成分载荷率为选择预测影响因素提供依据;针对各组样本分别建立BP神经网络模型,以土地利用和人口数据作为输入变量,小区交通发生量作为输出变量,以大连市城市交通调查数据为例对上述方法进行检验,并与传统回归模型预测结果进行比较.结果表明,在数据预处理基础上建立的BP神经网络模型具有较高预测精度.
Forecasting trip generation and attraction is the first component of the four-stage method in transportation planning, which determines the urban layout and construction of traffic facilities. To improve the accuracy of trip generation forecasting, K-means cluster analysis was used to divide traffic zones into several groups according to the population and employment. Principal component analysis was conducted to calculate the loading rate to principal components, providing the basis for choosing the influence factor. Finally, BP (Back Propagation) neural networks were set up to forecast trip generation; the input included land-use and population of each traffic zone; and the output was the trip generation. The methods were testified with the traffic survey data from city of Dalian, Liaoning province. Moreover, the results were compared with those obtained from multiple regression model. It is indicated that the BP neural network based on data pre-process produces better results in trip generation forecasting.