00396841

Component

http://onlinepubs.trb.org...s/trr/1984/971/971-013.pdf

https://scholar.google.co...rdle&publication_year=1984

Delay is being used increasingly as the primary indicator of level of service at signalized intersections, but for many traffic engineers delay estimation is a new task. Some of the currently available estimation techniques are introduced, and the assumptions on which they are based are examined. In general, these assumptions are unrealistic; so accurate delay estimates are not really possible. The difficulties are particularly acute when the arrival flows approach capacity. Some of the procedures avoid the worst of the problems at high flows by methods that, though they involve considerable mathematics, are based on modeling that is essentially qualitative rather than quantitative. Such methods abandon the quest for accuracy in favor of reasonableness: rather than attempting to provide right answers, they try to avoid answers that are terribly wrong. These models would seem to be useful as long as users do not expect too much from them, and the models can probably be somewhat improved. If accuracy is desired, however, a new generation of models that take more account of variations in travel demand over time is needed. The use of such models would require more information about traffic patterns than users are accustomed to providing.

This paper appeared in Transportation Research Record No. 971, Traffic Capacity and Characteristics. 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

00452357

HS-038 739

p. 96-105

1984

Transportation Research Record

0309037530

Figures (8) ; References (13)

Accuracy; Mathematical models; Signalized intersections; State of the art studies; Traffic delays

Highways; Operations and Traffic Management; I71: Traffic Theory

HSL, TRIS, TRB

Jan 31 1986 12:00AM

• ANALYSIS OF UNSIGNALIZED INTERSECTION CAPACITY
• ANOTHER LOOK AT STORAGE REQUIREMENTS FOR BANK DRIVE-IN FACILITIES
• AUTOMATED COLLECTION OF VEHICULAR DELAY DATA AT INTERSECTIONS
• CAPACITY, SPEED, AND PLATOONING VEHICLE EQUIVALENTS FOR TWO-LANE RURAL HIGHWAYS (DISCUSSION ANDD CLOSURE)
• COMPUTER SIMULATION TO COMPARE FREEWAY IMPROVEMENTS (ABRIDGMENT)
• DEVELOPMENT AND APPLICATION OF A MACROSCOPIC MODEL FOR RURAL HIGHWAYS
• DISCONTINUITY IN EQUILIBRIUM FREEWAY TRAFFIC FLOW
• DYNAMIC FREEWAY SIMULATION PROGRAM FOR PERSONAL COMPUTERS
• EVALUATING CAPACITIES OF ONE-LANE ROADS WITH TURNOUTS
• INVESTIGATION OF NETWORK-LEVEL TRAFFIC FLOW RELATIONSHIPS: SOME SIMULATION RESULTS
• LEFT-TURN EQUIVALENCIES FOR OPPOSED, SHARED, LEFT-TURN LANES
• LEVEL OF SERVICE CONCEPTS: DEVELOPMENT, PHILOSOPHIES, AND IMPLICATIONS
• PASSENGER CAR EQUIVALENTS FOR UNINTERRUPTED FLOW: REVISION OF CIRCULAR 212 VALUES
• ROLE OF ADAPTIVE DISCRETIZATION IN A FREEWAY SIMULATION MODEL
• SIMULATION OF TRAFFIC PERFORMANCE, VEHICLE EMISSIONS, AND FUEL CONSUMPTION AT INTERSECTIONS: THE TEXAS-II MODEL
• SIMULATION STUDY OF GUIDELINES FOR RURAL ROAD IMPROVEMENTS
• USE OF THE NCHRP SIGNALIZED INTERSECTION CAPACITY METHOD--A SOUTH AFRICAN EXPERIENCE
• VEHICLE-DETECTOR INTERACTIONS AND ANALYSIS OF TRAFFIC-ACTUATED SIGNAL CONTROLS