Study On Pedestrian Level Of Service At Signalized Intersection Based On Qualitative Reasoning

ABSTRACT:In the urban traffic, pedestrian is an important part, however, our country did not pay enough attention to pedestrian. In design research and management work, motor vehicles are being taken as the main consideration, so that pedestrian travel is no guarantee and LOS is not high. Therefore we need to advocate the "people-oriented" concept, and consider pedestrian earnestly as transportation. How to scientifically and rationally evaluate the pedestrian Level-of-Service has become a basic problem to be resolved.In view of this, supported by National Natural Science Foundation Project "Study on Several Issues of Pedestrian Level-of-Service at Signalized Intersection", pedestrian LOS was studied by qualitative and quantitative analysis based on qualitative reasoning as following:(1) The evaluation indexes of pedestrian Level-of-Service were proposed. Based on analysis of pedestrian crossing and previous research achievements, the evaluation indexes of pedestrian Level-of-Service which reflected mixed traffic characteristics of intersection were proposed from system view:pedestrian signal delay and pedestrian disturbing delay. The indicators not only reflected the pedestrian individual experience, but also considered the pedestrian's more comprehensive feelings in mixed traffic system.(2) The evaluation indexes'calculation models of Level-of-Service were built based on qualitative and quantitative reasoning analysis. Through the qualitative analysis of quantitative model of evaluation indexes, qualitative causal structures of evaluation indexes were established. Sample data were processed by wavelet analysis, which were extracted from the traffic survey and simulation, so as to get quantitative space division of parameters and the qualitative value and qualitative extents of indexes. Then according to the statistical analysis, the semi-quantitative calculation models of evaluation indexes which reflected the qualitative relationship between the parameters and evaluation indexes were calculated.(3) The classification standard of the pedestrian service level was put forward. Based on the discretization theory of class-related continuous attributes, the qualitative intervals of pedestrian signal delay and disturbing delay were graded.(4) An actual assessment of typical signalized intersections'pedestrian LOS and semi-quantitative model in Beijing was taken. The results show that the method is more practical than HCM2000.The innovation points include:(1) The evaluation indexes of pedestrian service level were proposed from system view.(2) The evaluation indexes'semi-quantitative models were built based on qualitative reasoning and quantitative analysis. Relative to the quantitative method, this method reflected uncertain relationship between parameters more scientifically.