Estimation of Dynamic PCU Using the Area Occupancy Concept at Signalised Intersections

Variability in vehicle mix necessitates the use of passenger car units (PCU), the widely accepted common measure in the estimation of saturation flow. Previous research works show that PCU for a vehicle is not static, but it varies with the level of interaction among vehicles. This study proposes a methodology based on area occupancy for the estimation of PCU. Number of standard car spaces (Ncs) corresponding to a vehicle category is determined based on area occupancy of subject vehicle category and occupancy time of equivalent homogeneous traffic stream. The variations in dynamic PCU values of vehicles with respect to traffic characteristics, control conditions and approach width are studied and it is found that all the cars in the traffic stream do not have PCU value one. It is also observed that PCU values of all categories of vehicles except small cars exhibit a decreasing trend with increase in its own proportion. In order to facilitate easy and quick estimation of dynamic PCU values, mathematical models are developed incorporating the effect of traffic composition and saturation flow.


  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 825-837
  • Monograph Title: International Conference on Transportation and Development 2016: Projects and Practices for Prosperity

Subject/Index Terms

Filing Info

  • Accession Number: 01603333
  • Record Type: Publication
  • ISBN: 9780784479926
  • Files: TRIS, ASCE
  • Created Date: Jun 20 2016 3:04PM