Analysis Of Traffic Safety On Signalized Roundabout Based On Traffic Conflict

Intersection is the important node of the city road network,meanwhile it is always the black spot.The signalized roundabout as a special form of intersection have played an important role in road traffic history.Hence,the safety condition of the signalized roundabout has a significant effect to safety level of the transportation of the whole road network.In order to reduce the accident rate,the safety of the signalized roundabout should be evaluated objectively so that they can advance the safety functions and the operation efficiency of the intersection.The traffic safety of the urban signalized roundabout along with traffic conflict technique,fuzzy mathematics and gray theory has been evaluated in this paper.Firstly,the methods of traffic safety evaluation of the intersection existed nowadays have been briefly introduced,and the merits and demerits of the safety evaluations based on statistic of traffic accidents have been analyzed.And that the superiority of traffic conflict technique used in the traffic safety evaluation of the intersection have been pointed out.Then through introducing the basic theory of traffic conflict technique,discussing the definition standard of traffic conflict,the paper provided an overview of the actualities of the domestic and overseas researches in the traffic conflict technique.Secondly,based on introducing the different classifications of signalized roundabout,the traffic conflict characteristics of different signalized roundabouts have been analyzed.Next,according to the operation characteristics of the signalized roundabout,the survey methods of traffic conflicts in the signalized roundabout have been put forwarded in the paper.Finally,combining with theory knowledge of traffic conflict technique,the fuzzy comprehensive evaluation method on the basis of traffic conflict technique with traffic conflict rates as evaluation index has been established under the fuzzy evaluation method.By taking the signalized roundabout of HuaShan in ShiShi city as an example,the traffic safety condition of HuaShan roundabout has been analyzed and evaluated.The evaluation result showed that the HuaShan roundabout was critical safety.Then the improvement measures of traffic safety have been advanced in the light of evaluation result and the availability of the improvement measures has been showed based on VISSIM.At the same time,in order to select more scientific and reasonable improvement measures,the decision method of improvement measures on the basis of gray relation analysis has been established in accordance with gray theory,then the improvement measures have been evaluated by quantitative decision in the paper.At last,the result indicated that the second scheme was better than the first scheme.