Study On The Model And Control Of The Traffic Flow Of Freeway Network

In recent years, along with the rapid development of freeway in our country, the freeway network is developing gradually. At the same time, in order to give full play to the overall efficiency of freeway network and raise the level of operation and service, freeway management has to be faced with higher requirement and greater challenge than before. Through the study on control measures and the model of freeway network, this dissertation provides scientific bases and technical strategies for the control of freeway network. The main content and achievements of this dissertation are:First, prediction of short-time traffic flow is studied in this dissertation. Through studying and comparing common methods about prediction of short-time traffic flow deeply, a prediction model for short-time traffic volume on the basis of Kalman Filtering Theory is made. Furthermore, the validity of this prediction model is approved by using actual data.Second, popular control measures of freeway are studied. In this part, dynamic on-ramp metering and variable speed limits are studied deeply, which are the most two efficient control measures, and the control model and algorithm for variable speed limits which are evaluated by simulation algorithm, are made.Third, a traffic flow model of freeway network which has Chinese characteristics on the basis of the simulation tool METANET is studied in this dissertation, through deep research, analysis and comparison of three decisions about making a model for freeway network proposed at the beginning. And the model of single freeway and METANET model of freeway network are compared to illustrate their occasions they fit, which provides traffic flow model to realize control of freeway network. Further, two extensions on the basic METANET model about considering the description of behavior of the off-ramp outflow when blocking occurs and the influence of variable speed limits are made which make the model fit practical situation more and the parameters of the model using Nanjing Lukou Airport Freeway as object are identified in this paper creatively.This dissertation is supported by the scientific research project: Research on Control of Monitoring System of Freeway Network and Interface Technology of Jiangsu Province, and the research has not only strong practical engineering background but also very important theoretical value, and supplies a gap in the field of modeling for the traffic flow of freeway network in China.