THE METROPOLITAN TORONTO INTERSECTION CAPACITY GUIDE

The values for saturation flow, together with the subsequent capacity calculations and volume/capacity ratios are intended as a guide for both estimating the capability of an at-grade signalized intersection to handle vehicular traffic, and evaluating the amount of spare capacity available for future growth of traffic at the intersection. In addition, it enables the user to optimize the performance of the signals by "balancing" the volume/capacity ratios, thereby achieving the minimum delay for each of the competing vehicular movements. The saturation flow regression equations are based on extensive research into field measurement techniques, augmented by an in-depth data collection program over the past eight years. This empirical approach has a sound theoretical basis, however, since the techniques are founded on the Australian Road Research Board method. Although these techniques provide accurate and reliable values if used correctly, they should always be supplemented, where possible, with actual field data or at least some brief observations to confirm with geometric layout, pavement markings, and general traffic characteristics that cannot be derived from a blueprint or historical counts. The methodology outlined in the guide will provide reasonable values for the majority of geometric and signal phasing configurations throughout Metropolitan Toronto. Additional interpretation may be required in some cases, however, to determine the impact of excessively wide lanes, turning radii, storage space, and on-street parking. A simple table look-up procedure cannot replace sound engineering judgement, which must be used in many instances where a "textbook case" does not exist. Care must be exercised in all cases therefore, to ensure precise and dependable results. (Author)

• Corporate Authors:

  Metropolitan Toronto Roads & Traffic Department

  401 Bay Street, 30th Floor
  Toronto, ONo,   Canada 
• Publication Date: 1982-8

Media Info

• Features: Figures; Tables;
• Pagination: 26 p.

Subject/Index Terms

• TRT Terms: Equations; Estimating; Highway capacity; Intersections; Methodology; Metropolitan areas; Percent saturation; Regression analysis; Traffic flow
• Uncontrolled Terms: Intersection capacity
• Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management; I71: Traffic Theory;

Filing Info

• Accession Number: 00368128
• Record Type: Publication
• Report/Paper Numbers: 4th Ed.
• Files: TRIS
• Created Date: Nov 30 1982 12:00AM