基于概率分析的应急交通救援需求预测模型

在开展应急救援需求特征分析的基础上,将需求分布问题归为管控条件下的运输优化问题,借鉴运筹学思想,建立基于运输问题的应急救援需求分布模型。其次,引入应急期限要求、通行能力约束、路径阻抗动态时变等影响因素,对运输问题模型进行改进。为便于求解,进一步将模型转化为基于概率分析的救援需求分阶段优化模型,该模型将车辆出行时间视为服从正态分布的随机变量,利用出行时间方差的调整反映不同阶段路径阻抗的变化,能够在满足救援响应时间的前提下,解得运输成本最小的需求矩阵。案例研究证明这个模型能够满足应急期限要求并刻画路径阻抗的动态时变特征,达到了预期效果。

Forecasting Model for Emergency Traffic Rescue Demands Based on Probability Analysis

By analyzing the characters of emergency traffic demands,the emergency traffic demand distribution is attributed to a transport optimization problem under the traffic control,and then,an emergency traffic rescue demand model based on transport problem is proposed according to the operational research theory.Subsequently,by introducing the factors including emergency response deadlines,capacity constraints and the dynamic time-varying path impedances,the original model is improved and converted into a probability-analysis-based optimization model,which overcomes the shortage of complicated computation.The optimized model takes the vehicle travel time as a normal distribution of random variables,reflects the changes of path impedance at different stages by adjusting the variance in the travel time,and then,the demand matrix with the minimum transport costs could be achieved under the premise of meeting the rescue response deadline.Finally,a case study demonstrates that the proposed model could satisfy the emergency rescue deadline requirements,and depict the dynamic time-varying characteristics of the path impedances as well.