Evaluation of the effective length of passing lanes on two-lane highways

ABSTRACT

This study presents an investigation into effective length of passing lanes on rural two-lane highways using field and simulation data. Field data from two study sites in Oregon were used to calibrate and validate the traffic simulation program used in this study. The calibrated simulation model was then used in evaluating the effective length of passing lane under different traffic levels and percent no-passing zones. Study results showed that the effective length of a passing lane is a function of traffic level as well as the percent no-passing zones for any segment of two-lane highway. Further, results confirmed that the operational benefits of passing lanes generally last for a significant distance downstream of the passing lane, with this distance varying in the range between 3 and 20 miles depending on traffic level and percent no-passing zones. Expectedly, higher traffic levels and higher percentage of no-passing zones were found to result in shorter effective lengths.

KEYWORDS:

• Two-lane highways
• platooning
• passing lanes
• effective length

Acknowledgments

The authors would like to acknowledge the financial support provided for this study by the National Cooperative Highway Research Program. Further, the authors would like to thank the respective staff at the Oregon Department of Transportation for providing the field data used in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Cooperative Highway Research Program (NCHRP) project 17-65.