Empirical Characteristics of Transit Travel Time Distribution for Commuting Routes

This paper conducted an empirical study on bus travel time distribution for commuting trips. The motivation of this paper is a common issue found in existing transit assignment models. In existing models, the travel time is usually assumed as normal distribution, which may not be the case in real world. In the study, the transit operations data and demand data for 14 bus routes in Nanning, China are used. The statistic analysis is based on the viewpoint of transit operator and that of commuters, respectively. The probability density functions of normal, lognormal, gamma as well as log-logistic distribution are tested to verify if they are fitted for the sample data. The findings in this paper confirmed that the use of normal distribution for transit travel time is not reasonable. The actual distribution is a highly-skewed distribution rather than a symmetric distribution like normal distribution. On one hand, the distribution properties have a significant correlation with distance and the number of passengers boarding between two bus stops. Bus vehicle travel time in peak hours is verified to be best fitted by log-logistic distribution under different time windows. On the other hand, travel time processed according to individuals has a higher mean value and a smaller deviation than those of vehicles. Such finding might be due to the centralization of departure time choice of commuting individuals. Thus, the vehicle travel time properties might not be good representative for the one experienced by commuters. Even if bus travel time distribution experienced by commuting individuals isn't proven to be well-fitted to the four probability density functions mentioned above, the travel time is still skew distributed. The findings from the study are useful for the further improvement of the existing transit assignment models on route choice and departure time choice used by planners and practitioners.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Xue, Yuan
  • Jin, Jing
  • Lai, Jie
  • Ran, Bin
  • Yang, Dongyuan
• Conference:
  • Transportation Research Board 90th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2011-1-23 to 2011-1-27
• Date: 2011

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 19p
• Monograph Title: TRB 90th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Bus transit; Bus transit operations; Commuting; Empirical methods; Public transit; Travel time; Work trips
• Subject Areas: Planning and Forecasting; Public Transportation; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01333040
• Record Type: Publication
• Report/Paper Numbers: 11-2827
• Files: TRIS, TRB
• Created Date: Mar 21 2011 2:13PM