Dissertation > Transportation > Road transport > Technical management of traffic engineering and road transport > Traffic engineering and traffic management > Line of traffic safety facilities > Traffic signals

Signal Control Method of Multstate Traffic Flow Based on Vehicle Delay Theory

Author DingHeng
Tutor ChenWuWei
School Hefei University of Technology
Course Vehicle Engineering
Keywords multi-state traffic flow signal control vehicle delay capacity traffic prediction
CLC U491.51
Type PhD thesis
Year 2011
Downloads 182
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The traffic flow in signalized intersection always embodies multi-state characteristic in terms oftime and space, influenced by a variety of factors, such as driving skill, traffic composition, signalcontrol, traffic management, traffic environment, etc. The existing signal control methods, whichhaven’t fully taken the distribution characteristic of traffic flow in intersection into account,causeintersections becoming the main areas of delay increasing in the road network and affect theoperation benefit of entire network. In order to solve the problem that the existing control methodcould not adapt to the intersection signal control in multi-state traffic conditions, the characteristic ofmulti-state traffic flow has been analyzed, traffic flow prediction method and capacity model ofintersection have been established, supported by the National Natural Science Foundation projects“Study on simulation and control strategy of driving cycle in mixed traffic environment”(No.70771036) and “The simulation of traffic flow segment and management measures empiricalresearch in plane intersection”(No.71071044), Furthermore, signal control methods and delayanalysis theory have been proposed. The research has been basically reflected in the followingaspects:(1) By analyzing the multi-state characteristic of traffic flow in terms of time and space, theinfluences have been analyzed from three aspects: driver, vehicle and highway. Decision methods ofmulti-state traffic flow and relatively steady-state one have been put forward, and the thresholdvalues of headway and traffic flow have been calibrated.(2) Combined with the feature that denseness function could approximate any distributioncharacteristic data with arbitrary degree of accuracy, dense infinite mixture Gamma distributionfunction has been introduced to establish the headway fitting method based on the maximumlikelihood algorithm, and then the accuracy has been verified by the investigation results.(3) Based on gap acceptance theory, the capacity model of unsignalized intersection has beenestablished, from analyzing the probability that minor road traffic flow passes through the headspaces of major road one, by the infinite mixture Erlang denseness distribution function.(4) Based on wavelet analysis theory, the combination forecasting model of short-timemulti-state traffic flow has been established with RBF neural network and Markov chains predictionmethods.(5) According to the variation feature of multi-state traffic flow in the daily traffic statisticalseries, denoise process of daily traffic series signal has been implemented via wavelet analyzing. Combined with the signal timing theory by F.Webster-B.Cobber, the control time division method ofmulti-state signalized intersection has been proposed.(6) According to the distribution characteristic of multi-state traffic flow and time-spaceresources in intersections, control methods have been established in three types: timing control,inductive control and predictive control.①For unparallel multi-state traffic flow intersections, the adjoint phase timing control methodhas been set up after adjusting the space resources and using phase optimization technique.②On account of small intersections with fewer entrance lanes and changeable traffic flow, thesynthesis benefit PI function with main traffic permitting in each phase has been established basedon the queuing theory. According to the conflict relationship of each direction in intersection,inductive signal control method with phase self-organization optimizing has been proposed.③With regard to multi-state traffic intersection where there are many entrance lanes,multifunctional lanes should be installed. According to the queuing theory and predicting outcome ofmulti-state traffic flow, the selecting model of multifunctional lanes direction has been presented,which takes the minimum total operational delay as optimization objective. Under the condition thateffective green time could satisfy maximum queue length passing through, every phase has beenrolling optimized. And in this case, the predictive control method on space resources dynamicoptimization in intersection installing multifunctional lanes has been proposed.(7) The denseness function probabilistic statistics of multi-state traffic flow has beenestablished on the foundation of random process theory. Combined with the phase changes ofdifferent strategies, such as timing control, inductive control and predictive control, the signalcontrol delay model of multi-state traffic flow has been proposed.(8) The effectiveness of control strategy of multi-state traffic flow and the accuracy of delayanalysis theory have been confirmed by the simulation using VISSIM and related software.

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