OVERTAKING LANES ON TWO- LANE RURAL HIGHWAYS

The thesis was submitted for the degree of Doctor of Philosophy in the Department of Civil Engineering, Monash University. It investigates the effects of overtaking lanes on the traffic performance of rural roads. Three main tasks were a) development of a simulation model for traffic on rural roads; b) data collection and validation of the model; c) application of the model to a study of overtaking lanes. A set of simulation programs was developed, and restricted to fairly level terrain and uncongested flow rates. While the simulation models lacked some of the complex features of other models, they were easily validated and easy to use and interpret. Field experiments were conducted to measure the speed and bunching of rural traffic, and changes in these parameters on entering and leaving overtaking lanes. These experiments provided a limited data set which could be used for model calibration and validation. Equipment developed for the experiments included thin metal and rubber strips for vehicle detection, and a microprocessor- based recording unit. Two observations were drawn from field data: traffic speed and bunching were found to change much more rapidly on entry to an overtaking lane than on return to a two- lane road. It was also found that field measures of bunching are sensitive to the criterion used. Field data were used in an evaluation of the simulation models and it was concluded that the models can be used with confidence, especially for comparative studies. Overtaking lanes were simulated for many road and traffic conditions and various layout and design options. Results may be used to estimate travel times and operating speeds for any level two- or four- lane road or overtaking lane proposal, and for any conditions of sight distance, traffic composition, desired speed, flow rate and directional split. An analysis of these results show that overtaking lanes offer a cost- effective method for improving travel time and level of service on two- lane rural roads. (TRRL)

  • Corporate Authors:

    Monash University

    Department of Civil Engineering
    Clayton, Victoria  Australia  3800
  • Authors:
    • Hoban, C J
  • Publication Date: 1980-12

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 302 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00342261
  • Record Type: Publication
  • Source Agency: ARRB
  • Report/Paper Numbers: Thesis
  • Files: ITRD, TRIS, ATRI
  • Created Date: Dec 22 1981 12:00AM