HOT Lane Buffer and Mid-Point Access Design Review Report

The purpose of this report is to provide an overview of buffer and midpoint access designs for concurrent flow, high occupancy toll (HOT) lanes that are either in operation or under study and recommended the preferred buffer and access designs for these facilities. HOT lanes are dedicated to transit, carpools and vanpools, but also allow solo drivers to use the facility for a toll when surplus capacity is available. With the application of a HOT lane facility, a single occupant vehicle (SOV) can choose to pay for the use of the surplus capacity in the lanes. Tolls are adjusted to assure that these lanes keep flowing even when the regular lanes are congested. The primary tasks completed for this report include: (1)Research on non-barrier-separated designs, locations and designs for access points, and enforcement measures through a literature review and survey of other state agency HOT and /or HOV lane designs; (2) Evaluation of the various design options including safety, cost, and performance; and (3) Documentation of the findings and design recommendations for future HOT lane facilities in the state of Washington. Based on the information gathered from existing and planned concurrent traffic flow, high occupancy vehicle (HOV) or HOT facilities, this report provides presents the following recommendations: (1) A preferred buffer width between a HOT lane and an adjacent general purpose lane of 4 feet, with a minimum recommended width of 2 feet if it is not feasible to provide a 4 foot buffer. (2) A continuous inside shoulder of 14 feet for enforcement and to serve as a breakdown lane, with a minimum 2-foot inside shoulder recommended to separate the travel lane from any barrier if the ideal width is not feasible. (3) Mid-point access location openings of 1,000 feet per lane change; with a minimum length of 500 feet. For a combined access (allowing both ingress and egress), the length of the access point should be at least 1,000 feet (twice the minimum acceptable lane change distance of 500 feet).


  • English

Media Info

  • Media Type: Print
  • Edition: Research Report
  • Features: Appendices; Figures; Photos; Tables;
  • Pagination: 75p

Subject/Index Terms

Filing Info

  • Accession Number: 01044299
  • Record Type: Publication
  • Report/Paper Numbers: WA-RD 651.1
  • Created Date: Mar 10 2007 1:48PM