00225157

Component

http://onlinepubs.trb.org...s/hrr/1967/172/172-003.pdf

DESIGNERS ARE REACHING A POINT WHERE THEY CAN NO LONGER HOPE TO ACCOMMODATE PROJECTED TRAFFIC DEMANDS WITH CONVENTIONAL FREEWAY DESIGNS. THE PROBLEMS OF NOT ENOUGH FREEWAY CAPACITY AND NOT ENOUGH MERGING CAPACITY ARE AGGRAVATED BY SEVERE UNBALANCES OF FLOW DURING PEAK HOURS. WHEN THE DIRECTIONAL DISTRIBUTION OF TRAFFIC ON A MULTILANE HIGHWAY IS GREATLY OUT OF BALANCE DURING PEAK HOURS THE CAPACITY OF A GIVEN SECTION CAN BE APPRECIABLY INCREASED BY DEVOTING MORE THAN HALF OF THE LANES TO THE PREDOMINANT DIRECTION OF FLOW. THIS PRINCIPLE OF REVERSE-FLOW OPERATION IS GRUDGINGLY BEING APPLIED TO FREEWAY DESIGN WITH LIMITED SUCCESS. THIS PAPER IS A GENERALIZATION OF THE REVERSE-FLOW FREEWAY CONCEPT IN THAT IT SUGGESTS SOME INTERCHANGE DESIGNS WHICH ENABLE INGRESS DIRECTLY TO AND FROM THE AT-GRADE STREET SYSTEM RATHER THAN THE OUTSIDE FREEWAY ROADWAYS. IN ADDITION TO PRESERVING THE INCREASED CAPACITY OF THE REVERSIBLE FREEWAY LANES, THIS INNOVATION SHOULD DOUBLE OR TRIPLE THE MERGING CAPACITY AT CERTAIN INTERCHANGES. A STEP- BY-STEP PROCEDURE FOR UTILIZING THIS NEW TYPE OF REVERSE- FLOW FACILITY IS EXPLAINED. THE GEOMETRICS OF THE PROPOSED INTERCHANGES ARE DISCUSSED IN DETAIL, COMPLETE WITH A PLAN- PROFILE, TYPICAL SECTION, AND PROPOSED SIGNALIZATION PHASING PLAN. /AUTHOR/

Paper sponsored by Committee on Geometric Highway Design and presented at the 46th Annual Meeting. 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.

01410124

pp 39-53

1967

Highway Research Record

Digital/other

Figures (7) ; References (6)

Freeways; Geometric design; Highway capacity; Highway design; Interchanges; Interchanges and intersections; Merging traffic; Peak hour traffic; Reversible traffic lanes

Design; Highways; Operations and Traffic Management

TRIS, TRB

Jul 21 1994 12:00AM

• DEVELOPMENT AND USE OF MODELS IN THE DESIGN OF HIGHWAYS
• SOME VISUAL ASPECTS OF HIGHWAY DESIGN
• SPACING OF INTERCHANGES AND GRADE SEPARATIONS ON URBAN FREEWAYS