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 t...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.展开更多
Accidents are in rising mode and became the main problem all over the world especially in Malaysia as the reasons including the condition of the road, driver＇s reaction and the road environment. Actually, those condi...Accidents are in rising mode and became the main problem all over the world especially in Malaysia as the reasons including the condition of the road, driver＇s reaction and the road environment. Actually, those condition also factors to execute the lane changing which experienced by all drivers such as in U-turn road segment. In approaching U-turn segment, drivers needed to make a decision whenever any disruption in front of them such as merging vehicle because they have their own perspective and desire. For that purpose, this research is focusing on the reaction of the driver in approaching the U-turn facility road segment especially in speed （V）, reaction time （RT） and distance where from those parameters and their relationships, the statistical model was developed and used in estimating the safe distances to execute the lane changing from the merging vehicle. The data were taken from the field and driving simulator to come out with the raw data. The field data were from video recording that has been used to simulate the driving simulator. Therefore, through the relationship between the RT, speed （V） and distance of the subject vehicle to the merging vehicle, the statistical model has been developed with the equation D.4MVUT = （13.448 ＋ 1.410 RT- 0.075 V）.展开更多
文摘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.
文摘Accidents are in rising mode and became the main problem all over the world especially in Malaysia as the reasons including the condition of the road, driver＇s reaction and the road environment. Actually, those condition also factors to execute the lane changing which experienced by all drivers such as in U-turn road segment. In approaching U-turn segment, drivers needed to make a decision whenever any disruption in front of them such as merging vehicle because they have their own perspective and desire. For that purpose, this research is focusing on the reaction of the driver in approaching the U-turn facility road segment especially in speed （V）, reaction time （RT） and distance where from those parameters and their relationships, the statistical model was developed and used in estimating the safe distances to execute the lane changing from the merging vehicle. The data were taken from the field and driving simulator to come out with the raw data. The field data were from video recording that has been used to simulate the driving simulator. Therefore, through the relationship between the RT, speed （V） and distance of the subject vehicle to the merging vehicle, the statistical model has been developed with the equation D.4MVUT = （13.448 ＋ 1.410 RT- 0.075 V）.
