Evaluating operational efficiency of split merge, diverge, and weaving solutions for reducing freeway bottleneck congestion

ABSTRACT

The speeds of traffic and freeway throughputs at the merge, diverge, and weaving areas are reduced significantly due to vehicle lane changes and increased traffic volumes. This study proposes a solution, referred to as split design (i.e. split merge, diverge, and weaving). The key concept is to make geometric changes to the existing ramp designs to create two merge or diverge points, such that potential conflicts of the mainline and ramp traffic can be distributed apart spatially. This potentially decreases unnecessary interactions between the mainline and ramp vehicles. This study also uses microscopic traffic simulation to assess operational efficiency of the proposed alternative geometric design; and to develop managerial insights for state DOTs to better design, enhance, and manage their freeway systems in the future. We find that, overall, the split design can potentially increase throughput by 6% to 9% and reduce delay by 35% to 80% across different scenarios.

KEYWORDS:

• Freeway bottlenecks
• split merge
• diverge
• weaving
• operational efficiency

Acknowledgments

This study is funded in part by the US Department of Transportation (Project Number: DTFH61-12-D-00030) and the University of Cincinnati Office of Research. The authors want to thank a few other team members for their contributions to paper: Kate Ritchey and Alexandra Kondyli. The work presented in this paper remains the sole responsibility of the authors.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Federal Highway Administration [DTFH61-12-D-00030];