Characterization and calibration of volume-to-capacity ratio in volume-delay functions on freeways based on a queue analysis approach

In the iterative traffic assignment process of travel demand models, the performance of road systems is primarily evaluated via volume-delay functions (VDFs). This paper attempts to systematically examine different ways of representing volume-to-capacity (v/c) ratios in the Bureau of Public Roads (BPR) function and propose a peak period-based calibrating framework from a freeway bottleneck modeling perspective. Based on a transient queueing state analysis, the proposed framework allows the authors to estimate the congestion period during which both speed and flow drop due to oversaturation. By characterizing the volume term in the v/c ratio as the queued demand after a bottleneck, the authors hope to show the connection between the speed-flow fundamental diagram with BPR curves through a well-defined demand over capacity ratio. The characterization of v/c ratios helps the authors estimate the hour-to-period factors that are commonly used to generate period capacity before assignments. The authors systematically calibrate different methods using both speed and volume measurements, in 15-min resolution, from freeways in the Phoenix metro area.

• Record URL:
  https://annualmeeting.mytrb.org/OnlineProgram/Details/15862
• Supplemental Notes:
  • This paper was sponsored by TRB committee ACP40 Standing Committee on Highway Capacity and Quality of Service.
• Corporate Authors:

  Transportation Research Board

  ,    
• Authors:
  • Wu, Xin (Bruce)
  • Dutta, Arup
  • Wang, Zhang
  • Zhu, Haidong
  • Livshits, Vladimir
  • Zhou, Xuesong (Simon)
• Conference:
  • Transportation Research Board 100th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2021-1-5 to 2021-1-29
• Date: 2021

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; References; Tables;
• Pagination: 23p

Subject/Index Terms

• TRT Terms: Bottlenecks; Calibration; Freeways; Highway capacity; Traffic assignment; Traffic congestion; Traffic models; Traffic queuing; Traffic volume
• Identifier Terms: U.S. Bureau of Public Roads
• Geographic Terms: Phoenix (Arizona)
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting;

Filing Info

• Accession Number: 01763969
• Record Type: Publication
• Report/Paper Numbers: TRBAM-21-04304
• Files: TRIS, TRB, ATRI
• Created Date: Feb 4 2021 10:57AM