A New Parametric Model for Freeway Capacity Based on Stochastic Approach: Case of an Iranian Freeway

Capacity of a road addresses its quantitative traffic carrying ability. Researchers have shown that capacity of a single road varies, having a stochastic nature instead of a constant value. In stochastic approach, capacity is treated as a random variable generated from a population, with a certain distribution function. Since type of capacity distribution function is generally not known with certainty, it needs to be assumed. Different distribution functions like Normal and Weibull have mostly been proposed as possible alternatives for developed countries. In this paper, in addition to the traditional estimation of the capacity, efficiency of the freeway, as a powerful objective performance measure is estimated. Also, by applying the models for censored data on empirical observations of Iranian freeway, a new parametric capacity distribution type is proposed for the freeway facilities. Compared with findings of other studies on German freeways, it is suggested that capacity distribution function could be characterized with left-skewedness.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AHB40 Standing Committee on Highway Capacity and Quality of Service.
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Shojaat, Siavash
    • Mamdoohi, Amir Reza
    • Saffarzadeh, Mahmoud
    • Parr, Scott A
  • Conference:
  • Date: 2016


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 16p
  • Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01594182
  • Record Type: Publication
  • Report/Paper Numbers: 16-6261
  • Files: TRIS, TRB, ATRI
  • Created Date: Mar 21 2016 4:42PM