Differences in Freeway Capacity by Day of the Week, Time of Day, and Segment Type

Capacity has traditionally been defined deterministically, and has been assumed to occur immediately before breakdown. Recent studies, however, have shown that the value of capacity, i.e., maximum throughput, is probabilistic, and does not always occur immediately before the breakdown. Four different types of flows (i.e., maximum pre-breakdown flow, breakdown flow, maximum queue discharge flow, and average queue discharge flow) referred to as “capacity flows” in this paper, are considered to examine how they differ by day of the week and time of the day, and whether they are significantly different by type of freeway segment. Speed and volume data were obtained, which were initially collected by RTMS (Remote Traffic Microwave Sensors) at the US-202 Southbound near Philadelphia, PA, from May to August 2004. The four types of flows described above were collected and distinguished by time period, day of the week, and segment type. In conclusion, the mean capacity flows were different during different times of the day, but were the same each day of the week. In comparing segment types, capacity flows are generally not equal between merging, diverging, weaving, and lane drop segments.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 27p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01049279
  • Record Type: Publication
  • Report/Paper Numbers: 07-2287
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 6:58PM