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Harmonization for Omnidirectional Progression in Urban Traffic Control
Author(s) -
Findler Nicholas V.
Publication year - 1999
Publication title -
computer‐aided civil and infrastructure engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.773
H-Index - 82
eISSN - 1467-8667
pISSN - 1093-9687
DOI - 10.1111/0885-9507.00155
Subject(s) - intersection (aeronautics) , harmonization , traffic flow (computer networking) , computer science , process (computing) , control (management) , real time computing , engineering , artificial intelligence , transport engineering , computer network , operating system , physics , acoustics
I describe harmonization as part of my work on distributed, knowledge‐based, real‐time, traffic‐adaptive control of street and highway ramp traffic signals. The control system developed in prior efforts includes a two‐stage learning process. The first stage optimizes the control of steady‐state traffic at a single intersection and over a network of streets. The second stage of learning, not related yet to harmonization, deals with the predictive/reactive control of dynamic traffic flow in street networks. However, the control regimes at the individual intersections do not consider the time behavior of adjacent intersection control regimes. Optimal traffic flow in street networks must be with reference to signalization, phasing, and harmonization of control at all intersections. Harmonization represents the best approximation to a coordinated omnidirectional progression (“green wave”). This means that the resulting control regime produces a minimum of the sum, over all intersections, of delay times due to red lights and of unused green periods, each contributing term being weighted by the respective traffic flow values. The system has been tested in the laboratory on a range of scenarios (in terms of geometries and traffic flows) and has been found to perform as expected.