DEVELOPING FREEWAY PRIORITY-ENTRY-CONTROL STRATEGIES

This paper describes the development and application of an analytical procedure for priority-entry-control strategies at freeway ramps. Vehicles with different numbers of occupants arriving at an on-ramp are differentiated, and and those vehicles with more occupants are given priority entry onto the freeway. The 2 primary objectives of the priority-control strategy are to maximize either the number of persons served or the number of passenger-miles traveled. The primary constraint is that the vehicular demand for each freeway section not exceed the vehicular capacity of that freeway section. Additional constraints such as maximum and minimum metering rates can be specified. The analytical procedure encompasses 2 models. The first is a simulation model that is deterministic and macroscopic and predicts freeway-traffic performance as a function of freeway design and allowable ramp inflows. The second is a decision model that has a linear programming formulation and selects a control strategy that meets specified objectives and constraints. The simulation model has been validated under field conditions, and the predicted traffic performance compares favorably to actual, measured traffic performance. The 3 models have been integrated and the composite model has been applied to the East Bayshore Freeway in the San Francisco Bay area, the Santa Monica Freeway in Los Angeles, and the Long Island Expressway to demonstrate its application and to provide the California Department of Transportation and the New York State Department of Transportation with results that could be considered for possible implementation. A series of investigations were undertaken with the computerized model to determine the sensitivity of the overall measures of effectiveness to practical constraints and to consider the consequences of such control strategies on changing the traffic-demand pattern and passenger-car occupancy distributions.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1975/533/533-010.pdf
• Summary URL:
  • https://scholar.google.com/scholar_lookup?title=DEVELOPING+FREEWAY+PRIORITY-ENTRY-CONTROL+STRATEGIES&author=K.+Ovaici&author=R.+Teal&author=J.+Ray&author=A.+May&publication_year=1975
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/030902384X
• Supplemental Notes:
  • Publication of this paper sponsored by Committee on Freeway Operations. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Ovaici, Khosrow
  • Teal, Roger F
  • Ray, James K
  • May, Adolf D
• Conference:
  • 54th Annual Meeting of the Transportation Research Board
  • Location: Washington District of Columbia
  • Date: 1975-1-13 to 1975-1-17
• Publication Date: 1975

Media Info

• Media Type: Print
• Features: References; Tables;
• Pagination: pp 122-137
• Monograph Title: Freeway Entry, Flow, and Control
• Serial:
  • Transportation Research Record
  • Issue Number: 533
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Expressways; Freeways; Highway capacity; Interchange ramps; Mathematical models; Measures of effectiveness; Physical access control; Ramp metering; Strategic planning; Traffic control; Traffic simulation; Vehicle occupancy
• Uncontrolled Terms: Access control; Effectiveness; Models
• Old TRIS Terms: Freeway capacity; Freeway ramps; Strategy
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00099668
• Record Type: Publication
• ISBN: 030902384X
• Files: TRIS, TRB
• Created Date: Nov 5 1975 12:00AM