Loading...

Correction of origin-destination martrix from traffic counts (case of city of Mashhad)

Aashtiani, H. Z ; Sharif University of Technology | 2001

110 Viewed
  1. Type of Document: Article
  2. Publisher: 2001
  3. Abstract:
  4. The trip demand information in the form of the origin-destination (OD) matrix is an essential input to the transportation studies. Obtaining such a matrix by conventional methods needs considerable amount of time, cost, and manpower. Since obtaining traffic volume data for the links of the transportation network is easy, recently many researchers have tried to obtain trip demand matrix by using this information. Among them, Spiess introduced the gradient method which is applicable for real large scale networks. The gradient method is an iterative procedure which starts from an initial O-D matrix and at each iteration tries to reach a matrix which generates flows closer to the observed flows and while staying close to the initial matrix as much as possible. In this papre, the gradient method has been implemented based on tow type of traffic assignment procedures, namely Frank-wolfe and Aashtiani algorithms (which both of them are based on traffic equilibrium), in EMME / 2 software and C programming enviro nments respectively. The resulting algorithms have applied to real network (city of Mashhad). In the implementation of the gradient method using complementarity assignment, a method has been introduced for increasing the convergence speed. The computational results for the case under study show that using the complementarity algorithm in the gradient method makes it about 34 times faster as compared with the Frank-wolfe assignment in EMME / 2 environment. Also for keeping predicted (corrected) O-D matrix as close as possible to the initial matrix, an improved gradient method has been introduced. For the network of the city of Mashhad, the improved method predicted a matrix which was very close to the initial matrix while generating flows in the links very close to the respective observed ones
  5. Keywords:
  6. Demand correction ; Equilibrium ; Observed volume ; Origin-destination matrix ; Traffic assignmet ; Traffic counts
  7. Source: Amirkabir (Journal of Science and Technology) ; Volume 12, Issue 46 , 2001 , Pages 149-162 ; 10150951 (ISSN)
  8. URL: https://www.sid.ir/paper/1107/en