Traffic congestion evaluation method based on congestion index

Traffic congestion evaluation method based on congestion index

  • CN 103,366,557 B
  • Filed: 07/25/2013
  • Issued: 06/22/2016
  • Est. Priority Date: 07/25/2013
  • Status: Active Grant
First Claim
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1. based on the traffic congestion evaluation method of congestion index, it is characterised in that comprise the steps:

  • 1) free stream velocity in each section in obtaining 24 hours, described free stream velocity is the travel speed of vehicle in the complete unimpeded situation of the less road of the volume of traffic;

    2) calculating index TTI hourage in each section, described hourage, index was that vehicle travels the ratio of the time travelling same distance needs with free stream velocity with present speed;

    3) according to hourage exponential quantity size the data in whole for road network sections a certain moment are carried out cluster analysis, the principle that in exponent data hourage of system-wide net is big as far as possible according to class inherited, class, difference is the least possible determines optimal classes;

    4) on the basis determine optimal classes, index hourage in all sections of road network is clustered, and obtain the maximum TTI value of each class, minimum TTI Zhi Helei center TTI value;

    5) for each class is asked it comprise the average of sample gradient-norm, all kinds of mapping range in congestion index are directly proportional to its gradient-norm, and congestion index scope 0-10 is distributed to each class;

    6) step 5 give each hourage index class be assigned with on the basis that congestion index is interval, membership function is designed in each class, it is converted into congestion index according to the numerical value of certain rule each apoplexy due to endogenous wind index hourage, and blocks up weight situation with congestion index correspondence from small to large;

    Wherein, in step 3, it is determined that the step of optimal classes is as follows;

    If index hourage in i-th section is sample ai, then

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