00621686

Component

http://onlinepubs.trb.org...trr/1991/1320/1320-011.pdf

https://scholar.google.co...anks&publication_year=1991

The issue of whether ramp metering can increase the capacity of freeway bottlenecks by prevention or delay of flow breakdown on the freeway main line is considered. A summary of the results of four case studies of metered bottlenecks in San Diego is presented. The hypothesis that flow decreases when it breaks down is confirmed, provided the hypothesis applies to individual lanes. Flow decreases ranging from 10% to less than 1% were observed in the left lane at the various study sites. When averaged across all lanes, flow decreased by about 3% at one site; there was no significant change at the other sites. It is concluded that this phenomenon is unlikely to provide a basis for metering at more than a few locations, because decreases in flow across all lanes are very small, sometimes nonexistent. Even where there are decreases in total flow, there is risk that metering will be counterproductive if it is too restrictive or begins too early.

This paper appears in Transportation Research Record No. 1320, Freeway Operations, Highway Capacity, and Traffic Flow 1991. 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

01407170

p. 83-90

1991

Transportation Research Record

0309051533

Figures (9) ; References (16) ; Tables (2)

Bottlenecks; Case studies; Freeways; Highway capacity; Ramp metering; Traffic flow

San Diego (California)

Highways; Operations and Traffic Management; I71: Traffic Theory

TRIS, TRB, ATRI

Apr 30 1992 12:00AM

• ALINEA: A LOCAL FEEDBACK CONTROL LAW FOR ON-RAMP METERING
• ASSESSMENT OF THE TRAFFIC EXPERIMENTAL AND ANALYSIS SIMULATION COMPUTER MODEL USING FIELD DATA
• BENEFITS OF CENTRAL COMPUTER CONTROL FOR DENVER RAMP-METERING SYSTEM
• CAPACITY AND DELAY CHARACTERISTICS OF TWO-WAY STOP-CONTROLLED INTERSECTIONS
• CHARACTERISTICS AND LEVEL-OF-SERVICE ESTIMATION OF TRAFFIC FLOW ON TWO-LANE RURAL ROADS IN FINLAND
• DELAY EFFECTS ON DRIVER GAP ACCEPTANCE CHARACTERISTICS AT TWO-WAY STOP-CONTROLLED INTERSECTIONS
• DEVELOPMENT OF APPROPRIATE DESIGN-HOUR VOLUMES FOR URBAN FREEWAYS IN LARGE TEXAS CITIES
• EMPIRICAL ANALYSIS OF CONGESTED TRAFFIC FLOW CHARACTERISTICS AND FREE SPEED AFFECTED BY GEOMETRIC FACTORS ON AN INTERCITY EXPRESSWAY
• ENHANCEMENT AND FIELD TESTING OF A DYNAMIC FREEWAY SIMULATION PROGRAM
• EVALUATION OF HIGH-VOLUME URBAN TEXAS FREEWAYS
• EXAMINATION OF THE SPEED-FLOW RELATIONSHIP AT THE CALDECOTT TUNNEL
• FLOW AND CAPACITY CHARACTERISTICS ON TWO-LANE RURAL HIGHWAYS
• FREEWAY CAPACITY DROP AND THE DEFINITION OF CAPACITY
• FREEWAY CONTROL USING A DYNAMIC TRAFFIC FLOW MODEL AND VEHICLE REIDENTIFICATION TECHNIQUES
• IMPROVED DATA SCREENING TECHNIQUES FOR FREEWAY TRAFFIC MANAGEMENT SYSTEMS
• INTEGRATED SYSTEM OF FREEWAY CORRIDOR SIMULATION MODELS
• LESS-THAN-TRUCKLOAD TRUCKING IN LOS ANGELES: CONGESTION RELIEF THROUGH TERMINAL SITING
• OPERATIONAL EVALUATION OF TRUCK RESTRICTIONS ON I-20 IN TEXAS
• PROCEDURE FOR VALIDATION OF MICROSCOPIC TRAFFIC FLOW SIMULATION MODELS
• PROPOSED ANALYTICAL TECHNIQUE FOR ESTIMATING CAPACITY AND LEVEL OF SERVICE OF MAJOR FREEWAY WEAVING SECTIONS
• REAL-TIME EXPERT SYSTEM APPROACH TO FREEWAY INCIDENT MANAGEMENT
• REAL-TIME KNOWLEDGE-BASED INTEGRATION OF FREEWAY SURVEILLANCE DATA
• SATURATION FLOW: DO WE SPEAK THE SAME LANGUAGE?
• SIMULATION OF CROWD BEHAVIOR AND MOVEMENT: FUNDAMENTAL RELATIONS AND APPLICATION
• SIMULATION OF TWO- AND FOUR-WAY STOP CONTROL
• THE TWO-CAPACITY PHENOMENON: SOME THEORETICAL ISSUES
• TOLL PLAZA CAPACITY AND LEVEL OF SERVICE
• TOWARD A NEW GERMAN GUIDELINE FOR CAPACITY OF UNSIGNALIZED INTERSECTIONS
• TRAFFIC OPERATION OF BICYCLE TRAFFIC