Distribution Characteristics of Vehicle Specific Power on Urban Restricted Access Roadways

The development of new fuel consumption and emission models, such as MOVES2009, creates the need to characterize traffic conditions by using the Vehicle Specific Power (VSP) distribution. However, in the existing transportation engineering, there has been the lack of knowledge of relationships between the VSP distribution and the commonly used traffic parameters, and the lack of models to develop the VSP distribution from traffic parameters. In order to examine how traffic conditions impact the VSP distributions, this study uses large samples of floating car data collected from the expressways in Beijing to associate the VSP distributions with various average travel speeds. After comprehensively examining the collected data, some regular patterns are found between the VSP distribution and the average travel speed. Specifically, when the average travel speed is higher than 20 km/h, the VSP distribution comes close to a normal distribution. The mean of the VSP distribution is the VSP value when cruising at the average travel speed, and the standard deviation could be expressed as a power function of the average travel speed. Based on these findings, a mathematical model for developing the VSP distributions is then derived by using the average travel speed. Finally, a comparitive analysis between the estimated and actual fuel consumption demonstrates that the VSP distributions developed by the proposed model are reliable and applicable for the estimation of fuel consumptions. This study indicates a possibility of developing VSP distributions mathematically for different road facilities and traffic conditions, which can be integrated practically and easily with traffic simulation models for fuel and emission estimations.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; References; Tables;
  • Pagination: 17p
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01152740
  • Record Type: Publication
  • Report/Paper Numbers: 10-0496
  • Files: TRIS, TRB
  • Created Date: Jan 25 2010 10:16AM