United Evaluation Model of Traffic Operation Level for Different Types of Urban Road

Abstract:

New concept of road level of service (LOS) is proposed,which defines LOS into two parts:level of facility supply and level of traffic operation.Under the direction of this new concept,the ratio of travel speed to free flow speed (FFS) is selected as the evaluation index of traffic operation.Then,a test of traffic operation evaluation for urban expressway and streets,in which the experts are invited to grade different traffic operation level,is carried out.The result shows that,by introducing the FFS into the evaluation index to consider the difference of facilities,the evaluation methods of operation level for urban expressway and streets can be united.Finally,based on the concept of fuzzy set,the functions of degree of subordination is given for different level of traffic operation with the threshold value for each level following.