Impacts of traffic flow arrival pattern on the necessary queue storage space at metered on-ramps

ABSTRACT

This paper compares queue lengths at the two different on-ramp configurations: arterial-to-freeway ramp and freeway-to-freeway connector. Mesoscopic queue length simulation models are developed based on the input-output method. The input-output method aims to model the traffic flow arrival profile; then, the mesoscopic simulation model generates random traffic volume to simulate the stochasticity of traffic flow. The simulation models are validated using field-collected data. Simulation results indicated that the traffic flow arrival pattern has significant impacts on ramp queue length; vehicle platoons released from the upstream signalized intersection tend to exacerbate ramp queue length. At metered ramps, the required queue storage length is found to be 5.7% of demand when demand is less than 500 vehicles per hour per lane (vphpl), or 3.9% when demand is greater than 500 vehicles per hour per lane (vphpl). In comparison, at metered connectors, the percent numbers are 4.7 and 2.1%, respectively.

KEYWORDS:

• Ramp metering
• queue length modeling
• platoon arrival
• random arrival
• mesoscopic simulation
• queue storage design

Acknowledgements

The authors thank Arafat Khan of the University of Nevada, Reno (UNR) for his constructive discussions; Yue Zhao and Anabel Hernandez of UNR for help with field data collection and extraction; and Erika Hutton of UNR for help with editing this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was sponsored by the California Department of Transportation (Caltrans) [grant number 65A0486].