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Modeling highway congestion index for a developing country: The Iran experience

Vaziri, M ; Sharif University of Technology | 2007

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  1. Type of Document: Article
  2. Publisher: Sharif University of Technology , 2007
  3. Abstract:
  4. This paper describes an attempt to develop congestion indices for a developing country with a limited sampling. Speed and flow rate information was collected from urban highway traffic flow videotaping in Iran. Video display provided information for traffic modeling when, similar to most of the developing nations, Iran does not have locally developed highway capacity manuals. Processing of the extracted data and traffic modeling provided free and capacity flow information for the selected freeway and principal arterial sections for the capital city of Tehran. The congestion indices were associated, in simple and logical models, with five traffic descriptive variables of travel speed, travel rate, delay rate, travel rate ratio and delay ratio, respectively. To calibrate the congestion index models, specific congestion levels were assessed by the index values under free and capacity flow conditions. The functional forms used in congestion index modeling were derived from the congestion rate of change, simple, reasonable and relevant assumptions. For comparison, index models, based on the US Highway Capacity Manual, HCM, speed and flow rate information, were also developed. The developed indices were suggested as feasible and included quick response measures for congestion monitoring and control when traffic management resources are often limited and scarce. Based on the preferences of a group of transportation professionals and university students, the relative importance of each of the individual indices, as average weighting value, was identified. Using the average weighting values, an overall congestion index was also developed. The overall congestion index was suggested as a complimentary or alternative measure for congestion intensity assessment and evaluation. The study findings were based on a rather limited database and were location specific; nevertheless, for quick response congestion index development, the applied methodology could be used by any developing country. The suggested indices have potential in traffic management and congestion mitigation. © Sharif University of Technology, February 2007
  5. Keywords:
  6. Developing countries ; Highway administration ; Iran ; Motor transportation ; Video recording ; Highway congestion index ; Highway traffic flow ; Videotaping ; Highway traffic control ; Developing world ; Motorway ; Traffic congestion ; Traffic management ; Transportation development ; Urban transport ; Asia ; Eurasia ; Middle East ; Tehran
  7. Source: Scientia Iranica ; Volume 14, Issue 1 , 2007 , Pages 1-10 ; 10263098 (ISSN)
  8. URL: http://scientiairanica.sharif.edu/article_2988.html