Mechanism of Early-Onset Breakdown at On-Ramp Bottlenecks on Shanghai, China, Expressways

The mechanism of early-onset breakdowns was studied at on-ramp bottlenecks on expressways in Shanghai, China. From four on-ramp breakdown events captured on video, key parameters were extracted: prequeue flow, queue-discharge flow, speed variation per minute, lane change (LC) times in the mainline lanes and the acceleration lane, LC types, and LC locations (longitudinal and lateral). A total of 1,583 LC samples were analyzed. The findings showed a great difference in LC patterns when breakdowns occurred earlier than normal (i.e., before the bottleneck reaches expected capacity). In the case of an early breakdown, most LCs were forced LCs that occurred near the downstream end of the bottleneck, which spread laterally rather quickly. In contrast, in normal breakdowns in the United States, LCs were mostly free LCs that occurred evenly along the bottleneck longitudinally but were concentrated in rightmost lanes laterally.

• Record URL:
  • https://doi.org/10.3141/2421-08
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=Mechanism+of+Early-Onset+Breakdown+at+On-Ramp+Bottlenecks+on+Shanghai%2c+China%2c+Expressways&author=J.+Sun&author=L.+Zhao&author=H.+Zhang&publication_year=2014
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9780309295154
• Authors:
  • Sun, Jian
  • Zhao, Li
  • Zhang, H Michael
• Publication Date: 2014

Language

• English

Media Info

• Media Type: Print
• Features: Figures; Photos; References; Tables;
• Pagination: pp 64–73
• Monograph Title: Traffic Flow Theory and Characteristics 2014, Volume 1
• Serial:
  • Transportation Research Record: Journal of the Transportation Research Board
  • Issue Number: 2421
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Bottlenecks; Highway operations; Highways; Lane changing; On ramps; Traffic flow; Traffic incidents; Travel patterns
• Geographic Terms: Shanghai (China)
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; I73: Traffic Control;

Filing Info

• Accession Number: 01516096
• Record Type: Publication
• ISBN: 9780309295154
• Report/Paper Numbers: 14-3516
• Files: TRIS, TRB, ATRI
• Created Date: Feb 27 2014 9:06AM