The yellow light dilemma zone is widely known as an area on the high-speed intersection ap- proach, where vehicles neither safely stop before the stop line nor proceed through the intersection dur- ing amber interval....The yellow light dilemma zone is widely known as an area on the high-speed intersection ap- proach, where vehicles neither safely stop before the stop line nor proceed through the intersection dur- ing amber interval. Within such an area, a vehicle might be involved in a right-angle crash or rear-end collision. This issue has been extensively discussed over five decades in traffic engineering field, cov- eting from theory to practice. However, few comprehensive review literatures on the amber signal di- lemma zone problems can be found. The objective of this paper is to summarize the evolution of yellow light dilemma zone researches. Basic definition and boundary of dilemma zone followed by driver be- havior and dilemma zone hazard measurement are depicted. At last, the future directions of yellow light dilemma zone research are discussed.展开更多
In the U.S.and worldwide,driver behavior within an area close to high-speed signalized intersections-the dilemma zone,can be a major safety concern especially for heavy trucks.A variety of mechanisms are available as ...In the U.S.and worldwide,driver behavior within an area close to high-speed signalized intersections-the dilemma zone,can be a major safety concern especially for heavy trucks.A variety of mechanisms are available as countermeasures for the dilemma zone problem.In Nebraska,the Department of Roads has developed and implemented an Actuated Advance Warning dilemma zone protection system.The system has been effective at improving traffic safety in isolated applications.However,the system is yet to be used at signalized intersections operating in the coordinated mode.This paper presents results from a simulation study that assessed the potential deployment of the system on arterials where the signals are closely spaced and operate in a coordinated mode.The analysis indicated that,on average,there were 30%,7%and 30%reductions in the number of rear-end,lane change and crossing conflicts.The system also improved relative productivity by processing more vehicles.展开更多
Under mixed traffic conditions prevailing on Indian roads,drivers show complex response when faced with yellow signal because lane assignment gets dynamic in nature.The present study analyzes the effect of surrounding...Under mixed traffic conditions prevailing on Indian roads,drivers show complex response when faced with yellow signal because lane assignment gets dynamic in nature.The present study analyzes the effect of surrounding vehicles on response of the drivers while facing dilemma at intersections.Although dilemma zone definitions hold true in case of homogeneous traffic mix,a statistical analysis is performed to check the consistency across the definitions under mixed traffic condition.Present study shows a significant difference in percentage of red light running in comparison to homogeneous traffic as reported by various studies.For carrying out the research,study locations are chosen in such a way to reflect diversity in road geometry,traffic composition and signal characteristics.The results deduced in this study indicate a strong correlation between the driver's decision making choice and the effect of presence of surrounding vehicle at the onset of yellow signal.The effect of critical time analysis has been found out to be one of the parameters other than critical distance in categorizing driver's aggressiveness while facing the yellow signal.In the process of identifying the statistical significance of dilemma zone definitions,it has been found that under heterogeneous traffic condition,drivers behave differently as compared to homogenous traffic when it comes to dilemma zone.It is observed that the percentage of vehicles crossing the intersection when faced with dilemma by violating the red light is 11.6%according to dilemma zone definition I whereas the definition II has yielded about 10.8%violation covering different vehicle types.The above violation figures derived based on the above definition is somewhat higher as compared to homogeneous traffic condition which is observed to be of the order of 5%-6%.展开更多
The primary objective of this work is to explore how drivers react to flashing green at signalized intersections. Through video taping and data procession based on photogrammetry, the operating speeds of vehicles befo...The primary objective of this work is to explore how drivers react to flashing green at signalized intersections. Through video taping and data procession based on photogrammetry, the operating speeds of vehicles before and after the moment when flashing green started was compared using paired-samples T-test. The critical distances between go and stop decisions was defined through cumulative percentage curve. The boundary of dilemma zone was determined by comparing stop distance and travel distance.Amber-running violation was analyzed on the basis of the travel time to the stop line. And finally, a logistic model for stop and go decisions was constructed. The results shows that the stopping ratios of the first vehicles of west-bound and east-bound approaches are 41.3% and 39.8%, respectively; the amber-light running violation ratios of two approaches are 31.6% and 25.4%, respectively;the operating speed growth ratios of first vehicles selecting to cross intersection after the moment when flashing green started are26.7% and 17.7%, respectively; and the critical distances are 48 m and 46 m, respectively, which are close to 44 m, the boundary of dilemma zone. The developed decision models demonstrate that the probability of go decision is higher when the distance from the stop line is shorter or operating speed is higher. This indicates that flashing green is an effective way to enhance intersection safety,but it should work together with a strict enforcement. In addition, traffic signs near critical distance and reasonable speed limitation are also beneficial to the safety of intersections.展开更多
基金jointly supported by the National Natural Science Foundation of China ( No . 51208238 )the Science & Technology Plan Program of Yunnan Province , China ( No . 2013CA025 )
文摘The yellow light dilemma zone is widely known as an area on the high-speed intersection ap- proach, where vehicles neither safely stop before the stop line nor proceed through the intersection dur- ing amber interval. Within such an area, a vehicle might be involved in a right-angle crash or rear-end collision. This issue has been extensively discussed over five decades in traffic engineering field, cov- eting from theory to practice. However, few comprehensive review literatures on the amber signal di- lemma zone problems can be found. The objective of this paper is to summarize the evolution of yellow light dilemma zone researches. Basic definition and boundary of dilemma zone followed by driver be- havior and dilemma zone hazard measurement are depicted. At last, the future directions of yellow light dilemma zone research are discussed.
文摘In the U.S.and worldwide,driver behavior within an area close to high-speed signalized intersections-the dilemma zone,can be a major safety concern especially for heavy trucks.A variety of mechanisms are available as countermeasures for the dilemma zone problem.In Nebraska,the Department of Roads has developed and implemented an Actuated Advance Warning dilemma zone protection system.The system has been effective at improving traffic safety in isolated applications.However,the system is yet to be used at signalized intersections operating in the coordinated mode.This paper presents results from a simulation study that assessed the potential deployment of the system on arterials where the signals are closely spaced and operate in a coordinated mode.The analysis indicated that,on average,there were 30%,7%and 30%reductions in the number of rear-end,lane change and crossing conflicts.The system also improved relative productivity by processing more vehicles.
基金The authors would like to thank senior colleagues and technical staff for their continuous support for carrying out this project as well as director,Central Road Research Institute,New Delhi,for allowing us to take up this work as an in-house R&D project(OLP-0597).
文摘Under mixed traffic conditions prevailing on Indian roads,drivers show complex response when faced with yellow signal because lane assignment gets dynamic in nature.The present study analyzes the effect of surrounding vehicles on response of the drivers while facing dilemma at intersections.Although dilemma zone definitions hold true in case of homogeneous traffic mix,a statistical analysis is performed to check the consistency across the definitions under mixed traffic condition.Present study shows a significant difference in percentage of red light running in comparison to homogeneous traffic as reported by various studies.For carrying out the research,study locations are chosen in such a way to reflect diversity in road geometry,traffic composition and signal characteristics.The results deduced in this study indicate a strong correlation between the driver's decision making choice and the effect of presence of surrounding vehicle at the onset of yellow signal.The effect of critical time analysis has been found out to be one of the parameters other than critical distance in categorizing driver's aggressiveness while facing the yellow signal.In the process of identifying the statistical significance of dilemma zone definitions,it has been found that under heterogeneous traffic condition,drivers behave differently as compared to homogenous traffic when it comes to dilemma zone.It is observed that the percentage of vehicles crossing the intersection when faced with dilemma by violating the red light is 11.6%according to dilemma zone definition I whereas the definition II has yielded about 10.8%violation covering different vehicle types.The above violation figures derived based on the above definition is somewhat higher as compared to homogeneous traffic condition which is observed to be of the order of 5%-6%.
基金Project(51208451)supported by the National Natural Science Foundation of ChinaProject(10KJB580004)supported by the Natural Science Foundation for Colleges and Universities of Jiangsu Province,ChinaProject supported by the New Century Talents Project of Yangzhou University,China
文摘The primary objective of this work is to explore how drivers react to flashing green at signalized intersections. Through video taping and data procession based on photogrammetry, the operating speeds of vehicles before and after the moment when flashing green started was compared using paired-samples T-test. The critical distances between go and stop decisions was defined through cumulative percentage curve. The boundary of dilemma zone was determined by comparing stop distance and travel distance.Amber-running violation was analyzed on the basis of the travel time to the stop line. And finally, a logistic model for stop and go decisions was constructed. The results shows that the stopping ratios of the first vehicles of west-bound and east-bound approaches are 41.3% and 39.8%, respectively; the amber-light running violation ratios of two approaches are 31.6% and 25.4%, respectively;the operating speed growth ratios of first vehicles selecting to cross intersection after the moment when flashing green started are26.7% and 17.7%, respectively; and the critical distances are 48 m and 46 m, respectively, which are close to 44 m, the boundary of dilemma zone. The developed decision models demonstrate that the probability of go decision is higher when the distance from the stop line is shorter or operating speed is higher. This indicates that flashing green is an effective way to enhance intersection safety,but it should work together with a strict enforcement. In addition, traffic signs near critical distance and reasonable speed limitation are also beneficial to the safety of intersections.
