Queue Storage Design for Metered On-Ramps

Abstract

Queue storage at a metered freeway on-ramp is an essential design element for metered on-ramps to prevent on-ramp queue from extending beyond on-ramps. In this paper, various existing methodologies that are used to size the queue storage at metered on-ramps were first reviewed. It was found that queue storage sized using 7% of peak hour on-ramp demand is widely accepted in practice. A limited dataset collected in California helps provide some reality check for this method. It is recommended that queue storage be recognized as an indispensable design element at metered on-ramps, and detailed sizing guidance be developed in the highway geometric design policy of the American Association of State Highway and Transportation Officials (AASHTO).