Study On Local Responsive Ramp Metering Of Freeway

Comply with the society and economic development in our country, freeway construction is very hot. Freeway promotes the economic development largely, accelerates people and goods circulation, and enhances society contact. But the traffic volume in freeway is increased swiftly, especially freeway in national trunk and economy developed zone, the traffic volume is approach saturation in peak hours. When the weather changed, the traffic incident happened or the freeway geometry was not very good the traffic jam will appearance easily, those request effective freeway management and control methods. Freeway management and control methods include detect and manage traffic jam and incident, ramp control, mainstream control, corridor control, weather inspect and manage, charge manage and traffic information provide and manage. Freeway on-ramp metering control is direct control with the entrance traffic volume, it makes the traffic volume distributing with reason, uses the freeway capacity abundantly, and eliminates or decreases the collision and accident when the traffic flow convergence, is the primary means of freeway traffic control.The thesis summarize the typical ramp metering algorithms in home and abroad, contact our country freeway practice, with the likelihood of arisen traffic jam and over-long on-ramp queue phenomena on freeway, design local response metering algorithm ALINEA/Q/BN for freeway on-ramp, and use VISSIM software simulate normally, over-long ramp queue and exist the traffic bottleneck in freeway mainstream three traffic states with no control, ALINEA and ALINEA/Q/BN three control projects metering, analyze and compare the traits of three control project, testify the ALINEA/Q/BN is more effectively.The thesis comprises of 5 chapters and chapter 3 and 4 is the key:Chapter one introduce the thesis research backgrounds and meanings, from current freeway construction and management status analyze the necessity and essentiality of ramp metering control. Summarize the ramp metering control research actuality in home and abroad, analyze the trends and emphases of ramp metering control research. Put forward context chapter arrange.Chapter two summarize the freeway traffic control system, introduce and compare mainstream, ramp, corridor control three types of control system. Discuss the affection and meet condition of on-ramp metering control, and compare the on-ramp metering control fashion. Introduce the classification of ramp metering strategy and algorithm, particular discuss the overseas application and research hot algorithms and metering theories such as: the ALINEA and its extension, Zone algorithm, Seattle Bottleneck algorithm, SWARM algorithm etc., and list theirs shortcomings and merits. Introduce the hotspot and difficulty algorithms of ramp metering such as Linear Programming algorithm, Fuzzy Logic algorithm, un-recurrently traffic congestion metering model, Artificial Neural Networks algorithm etc..Chapter three analyze the shortcomings and merits of ramp integrate coordinated control and local metering, fix time and response control. Combination the ramp idiographic practice of our country, put forward the local responsive ramp metering algorithm ALINEA/Q/BN for suit the freeway traffic station when over-long ramp queue or exist traffic bottleneck, analyze the detector distribution and the detect data of the algorithm need. At the end, design the framework of the algorithm, and detailed design the emphasis issues of the ALINEA/Q/BN algorithm as traffic bottleneck identification, BMR calculate confirmation, over-long ramp queue detect, QMR calculate confirmation, the affection of QMR and choose the parameters of ALINEA as regulator parameter, desired occupancy, update cycle of metering rate, location of downstream detector etc..Chapter four simply introduce the VISSIM software of the ramp metering algorithm simulation, calculate the capacity of freeway basic section and ramp in simulation, receive the basis of setting traffic demands in simulation, certificate the parameters of the algorithm as freeway geometry, regulate traffic light time, the range of ramp metering rate etc.. Simulate with no control, ALINEA and ALINEA/Q/BN three control schemes for freeway volume normally, over-long ramp queue and exist mainstream bottleneck three traffic states, gained the correlative data and drawled the diagrams, research has proven: ALINEA/Q/BN is capable of provides preferable control affection in three traffic states compare with no control and ALINEA, it can avoids over-long ramp queue and alleviates the congestion after traffic bottleneck appearance, and makes the traffic flow smoothness. Summarize the ALINEA/Q/BN algorithm ultimately.Chapter five conclusions and the futures work. The main contents of the thesis are reviewed, and then exist problems are pointed out. Finally, the problems that need to further study in the future are proposed.