Assessment and validation of managed lanes weaving and access guidelines.

Details

• Creators:
  Williams, James C. ; Mattingly, Stephen P. ; Yang, Chulsu
• Corporate Creators:
  University of Texas at Arlington. Department of Civil and Environmental Engineering
• Corporate Contributors:
  Texas. Dept. of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Managed lanes
  • Traffic lanes
  • Weaving sections
  • Weaving traffic
  • Highway capacity Managed Lane Access, Freeway Weaving,
  • Microscopic Simulation, Weaving Capacity
• Publication/ Report Number:
  FHWA/TX-09/0-5578-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Corporate Publisher:
  Texas. Department of Transportation
• Abstract:
  The goal of this project was to establish spacing requirements for access points to managed lanes ; with respect to the location of entrance and exit ramps on the general purpose lanes of the freeway. Traffic ; entering the freeway destined for the managed lane must weave across the general purpose lanes. Traffic ; exiting the freeway from the managed lane must also perform this maneuver. ; The results are based on microscopic simulation using the VISSIM model. The simulation model ; was carefully calibrated using data collected on IH 635 (LBJ Freeway) in Dallas, Texas. A genetic algorithm ; was used in the calibration. The model was subsequently validated using data collected at a nearby site ; along IH 635. ; The weaving was analyzed as a Type C two-sided weave. Capacity was estimated by gradually ; increasing flow in the general purpose lanes for each set of conditions until the simulation model ; throughput was less than the input flows, indicating the formation of queues. The specific conditions ; included ramp flows (500 to 1250 veh/hour), ramp to managed lanes flows (100 to 400 veh/hour), general ; purpose lanes to managed lane flows (200 to 800 veh/hour), and length of weave (1000 to 4000 feet). ; The principal determinant for spacing was the weaving flow (ramp to managed lane flow), with a ; minimum weaving distance of 2000 to 3500 feet for flows from 200 to 400 veh/hour. A desirable ; minimum distance of 4000 feet was found. All results were for four general purpose lanes.
  More +
• Format:
  PDF
• Funding:
  Project 0-5578
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18302/dot_18302_DS1.pdf
• File Type:
  [PDF - 1.24 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:3c74eaa0150387060ea45cf80e601f682f7b95adfc49884690788a0a7100b5a700bac2f3be52565c32dd9289f1bcec7bd82280c83dd2544c73f16cb2760757d3