Incorporating Driveway Density into an Arterial Corridor Travel Time Index Estimation Model

This paper describes research with the objective of developing a corridor arterial model to estimate the travel time index (TTI) with consideration of driveway density. The TTI is the ratio of the travel rate (minutes per mile) during the peak period to the travel rate (minutes per mile) during the off-peak period. This paper describes two models to assist transportation professionals in estimating the TTI in the arterial environment during light and moderate congestion conditions. Researchers developed the models based upon a 2.6-mile major arterial corridor in College Station, Texas. To address limitations of existing models, the models presented in this paper 1) consider driveway density, 2) are corridor-based, 3) are a function of generally-available or easy-to-obtain independent variables, 4) are calibrated and validated with extensive field data, and 5) explain a relatively high degree of variability. The use of TTI also makes the models more transferable. The model for moderate congestion conditions (TTI values up to approximately 2.8) is a function of traffic volume, driveway density, signal green time relative to the cycle time (g/C), and signal coordination condition. The model for light congestion conditions (TTI values up to 1.35) is based upon traffic volume and g/C along the corridor. Intuitively, when congestion levels are relatively higher, the research found that driveway density was an important prediction variable for TTI along the arterial corridor. This paper also provides a description with steps to assist analysts in using the models to estimate TTI for planning purposes. The research is of benefit to transportation professionals and decision-makers who are responsible for tracking mobility along roadways of interest and for prioritizing roadway improvements. The research is also beneficial to practitioners and researchers promoting the importance of access management (i.e., driveway density), especially during congested conditions.


  • English

Media Info

  • Media Type: DVD
  • Features: Figures; Photos; References; Tables;
  • Pagination: 19p
  • Monograph Title: TRB 89th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01154409
  • Record Type: Publication
  • Report/Paper Numbers: 10-2670
  • Files: TRIS, TRB
  • Created Date: Jan 25 2010 11:17AM