城市快速路出口匝道行车风险评价模型及应用验证

Research on driving-risk evaluation model and application verification of urban expressway exit-ramp

为了准确描述城市快速路出口匝道行车风险,针对城市快速路出口匝道区域,提出了基于影响系数的出口匝道行车风险模型。首先对城市快速路出口匝道进行区段划分,接着分析城市快速路出口匝道行车风险源及其影响因素。通过分析城市快速路出口匝道区域换道行驶和跟驰行驶状态下车辆碰撞的安全限制条件,选取对应状态下的车辆行驶风险函数和评价指标,运用影响系数法确定各评价指标的聚合权重,从而建立城市快速路出口匝道区域行车风险评价模型,并提出行车风险等级对照表。最后利用模型对昆明市北二环快速路小屯立交至海屯路出口匝道区域进行行车风险计算,确定行车风险等级,并确定该出口匝道区域换道状态和跟驰状态下高风险路段。研究表明,该模型对城市快速路出口匝道区域行车风险能有效辨识及划分,能够为城市快速路交通安全管理提供有力支撑。

To describe the driving-risk of urban expressway exitramp accurately,this paper developed an exit-ramp driving-risk evaluation model based on the influence coefficient.First,by literature review and analysis,the paper divided the urban expressway exit-ramp area into 4 parts:the interweaving area,the main line-ramp diversion area,the downstream area of the main line,and the exit-ramp area.Then we analyzed the driving-risk sources and influencing factors of urban expressway exit-ramp.The 13 factors were divided into 3 categories.Second,this article selected 5 evaluation indicators under corresponding conditions through analyzing the safety conditions of traffic crashes in the urban expressway exit-ramp area during car lane-changing and car-following conditions,including the speed,the speed difference,the traffic volume,the longitudinal gradient,and the friction coefficient.Then we used the influence coefficient method to determine the aggregate weight of each evaluation indicator and multiplied the index value and weight of the corresponding index.The paper established a driving-risk assessment model for the urban expressway exit-ramp area and determined the driving-risk level comparison table.The drivingrisk of the exit-ramp area was divided into 3 levels:general risk,high risk,and higher risk.Finally,the article calculated the driving-risk of the exit-ramp area from Xiaotun to Haitun Road on Kunming North Second Ring Expressway by using this assessment model.Then this model determined the high-risk areas of the lane-changing condition and car-following condition in this exit-ramp area.The result indicates that the model built in this article can effectively identify and divide the driving-risk sections in the urban expressway exit-ramp area,which can provide strong support for the traffic safety management of the urban expressway.