摘要
The location of U-turn bays is an important consideration in indirect driveway left-turn treatments.In order to improve the performance of right-turns followed by U-turns（RTUTs）,this study evaluates the impacts of the separation distances between driveway exits and downstream U-turn locations on the safety and operational performance of vehicles making RTUTs.Crash data are investigated at 179 selected roadway segments,and travel time data are measured using video cameras at 29 locations in the state of Florida,USA.Crash rate models and travel time models are developed based on data collected in the field.It is found that the separation distance between driveway exits and downstream U-turn locations significantly impacts the safety and operational performance of vehicles making right turns followed by U-turns.Based on the research results,the minimum and optimal separation distances between driveways and U-turn locations under different roadway conditions are determined to facilitate driver use of RTUTs.The results of this study can be used for future intersection improvement projects in China.
由于掉头口位置选取是城市道路远引掉头技术中的重要因素,为了提高远引掉头实施效果,从安全和运行效率2个方面对远引掉头口和上游支路出口之间的距离对远引掉头实施效果的影响进行了分析.对美国佛罗里达州开展了广泛的数据采集,共得到179个不同路段的历史事故数据,采用录像观测法获得了29个不同路段的交通流运行数据.在实测数据的基础上构建了事故率模型和车辆运行时间模型.研究表明,掉头口和上游支路之间的间距对掉头车辆的安全性和运行效率有显著影响.根据研究结果,提出了针对不同道路条件下设置掉头口和上游支路出口应保证的最短距离以方便司机使用掉头口.分析研究结果可为国内交叉口改造提供借鉴.
基金
JingjingLiuPaniversity,Nanjing210096Therehavebeencon
