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Modelling transit effects in signalized urban networks
14
Recent Doctoral Dissertations
as a new traffic adaptive strategy developed in this research were used in the study to investigate their relative performance in addressing the above problems of dynamic flow variations in a signalized network. In addition, pertinent issues related to the dynamic traffic control strategies are also examined. The results from the simulation studies in this research indicate that traffic adaptive control strategies perform better than the pretimed multi-dial control having off-line optimized timing plans which are implemented based on the time-of-day criteria. The results also indicate the feasibility of the concept of distributed control in traffic control systems by using intelligent traffic controllers which can make timing plan decisions independently but collectively.
Modelling transit effects in signalized urban networks. Jacques, Maria Alice Prudencio, Ph.D. University of Waterloo (Canada), 1993. 274 pp. Adviser: Sam Yagar ISBN: O-315-84439-6.
is then determined according to this modified GOPattern. The model has been incorporated into the TRANSYT-7F program. It encourages the TRANSYT optimizer to find optimal settings which minimize the adverse effects of transit loading on-line during a green phase. The developed model was applied to part of the Queen Street transit corridor in Toronto. The results of this application indicate the potential benefits and limitations in using the developed model. They also indicate that the TRANSYT-7F optimizer needs to be revised to take full advantage of the more realistic traffic behavior representation, as provided by the proposed model, to generate optimal signal settings for urban signalized networks.
Nodal capacity-restricted dynamic modeling of network traffic flows for freeway/signalized arterial corridor traffic control. Lee, Young-Ihn, Ph.D. Texas A & M University, 1992. 140 pp. Chair: Raymond A. Krammes.
OrderNumberDA93-15356
OrderNumberDANN-84439 Near-side transit stops at intersections are convenient in terms of user transfer from one transit route to another, and are very commonly used in North America. However, when transit vehicles stop to load/unload passengers on the travelled right-of-way (on-line) they hold up the other traffic, obstructing its flow. The pre-timed traffic control model TRANSYT, and its American version TRANSYT7F. are used throughout the world for traffic signal coordination in urban networks. This model is the only commonly used traffic control model that explicitly deals with transit operations in urban networks, determining optimal signal settings to benefit transit. The objectives of the research described in this thesis are to study the traffic interactions caused by transit loading and to develop a simulation model which allows the representation of transit operations (at near-side stops) in fixed-time signalized urban networks. In order to reasonably accommodate sequences of cycles with and without transit, this deterministic simulation model usually considers a simulation time period equal to two normal cycles, which is in turn divided into the increments of equal duration (steps), typically about two seconds long. The traffic behavior is then simulated for each step, on a linkby-link basis, based on the three following types of flow profiles: the arrival flow profile (IN-Pattern), the output flow profile (OUT-Pattern), and the saturation output flow profile (GO-Pattern). The developed model is able to represent the effect of near-side transit stops on the other traffic by adjusting the GO-Pattern to represent either the total or partial blockage of the approaches when transit loads/unloads at green signal indications. The OUT-Pattern
This dissertation documents the development of a nodal capacity-restricted dynamic network model for evaluating corridor traffic management strategies. The basic requirement of corridor control models is that the models should consider both the diversion and restriction aspects of the corridor traffic management philosophy, but dynamic traffic assignment models for evaluating the diversion effects of those strategies are not well developed. The purpose of this study is to develop a new dynamic assignment model that is compatible with simulation models for corridor traffic management purposes. A special feature of this model is its ability to manage different flow characteristics for freeways and arterials, queue and queue spillback, and uncompleted trips for freeway/ signalized arterial corridors. The process of the dynamic nodal capacity-restricted network model was illustrated with a directed example network. The model was also applied to a portion of the Southwest Freeway corridor in Houston. Comparisons of both the logic of the modeling concepts and the consistency of assignment and simulation results suggest that the nodal capacity-restricted dynamic network model is superior to the existing models for corridor traffic management applications.
Optimization of intersection signal parameters within equilibrium route choice models. Said, Kawkeb A. H., Ph.D. University of Illinois at Chicago, 1993. 227 pp. Order Number DA93-35147
Recent Doctoral Dissertations
as a new traffic adaptive strategy developed in this research were used in the study to investigate their relative performance in addressing the above problems of dynamic flow variations in a signalized network. In addition, pertinent issues related to the dynamic traffic control strategies are also examined. The results from the simulation studies in this research indicate that traffic adaptive control strategies perform better than the pretimed multi-dial control having off-line optimized timing plans which are implemented based on the time-of-day criteria. The results also indicate the feasibility of the concept of distributed control in traffic control systems by using intelligent traffic controllers which can make timing plan decisions independently but collectively.
Modelling transit effects in signalized urban networks. Jacques, Maria Alice Prudencio, Ph.D. University of Waterloo (Canada), 1993. 274 pp. Adviser: Sam Yagar ISBN: O-315-84439-6.
is then determined according to this modified GOPattern. The model has been incorporated into the TRANSYT-7F program. It encourages the TRANSYT optimizer to find optimal settings which minimize the adverse effects of transit loading on-line during a green phase. The developed model was applied to part of the Queen Street transit corridor in Toronto. The results of this application indicate the potential benefits and limitations in using the developed model. They also indicate that the TRANSYT-7F optimizer needs to be revised to take full advantage of the more realistic traffic behavior representation, as provided by the proposed model, to generate optimal signal settings for urban signalized networks.
Nodal capacity-restricted dynamic modeling of network traffic flows for freeway/signalized arterial corridor traffic control. Lee, Young-Ihn, Ph.D. Texas A & M University, 1992. 140 pp. Chair: Raymond A. Krammes.
OrderNumberDA93-15356
OrderNumberDANN-84439 Near-side transit stops at intersections are convenient in terms of user transfer from one transit route to another, and are very commonly used in North America. However, when transit vehicles stop to load/unload passengers on the travelled right-of-way (on-line) they hold up the other traffic, obstructing its flow. The pre-timed traffic control model TRANSYT, and its American version TRANSYT7F. are used throughout the world for traffic signal coordination in urban networks. This model is the only commonly used traffic control model that explicitly deals with transit operations in urban networks, determining optimal signal settings to benefit transit. The objectives of the research described in this thesis are to study the traffic interactions caused by transit loading and to develop a simulation model which allows the representation of transit operations (at near-side stops) in fixed-time signalized urban networks. In order to reasonably accommodate sequences of cycles with and without transit, this deterministic simulation model usually considers a simulation time period equal to two normal cycles, which is in turn divided into the increments of equal duration (steps), typically about two seconds long. The traffic behavior is then simulated for each step, on a linkby-link basis, based on the three following types of flow profiles: the arrival flow profile (IN-Pattern), the output flow profile (OUT-Pattern), and the saturation output flow profile (GO-Pattern). The developed model is able to represent the effect of near-side transit stops on the other traffic by adjusting the GO-Pattern to represent either the total or partial blockage of the approaches when transit loads/unloads at green signal indications. The OUT-Pattern
This dissertation documents the development of a nodal capacity-restricted dynamic network model for evaluating corridor traffic management strategies. The basic requirement of corridor control models is that the models should consider both the diversion and restriction aspects of the corridor traffic management philosophy, but dynamic traffic assignment models for evaluating the diversion effects of those strategies are not well developed. The purpose of this study is to develop a new dynamic assignment model that is compatible with simulation models for corridor traffic management purposes. A special feature of this model is its ability to manage different flow characteristics for freeways and arterials, queue and queue spillback, and uncompleted trips for freeway/ signalized arterial corridors. The process of the dynamic nodal capacity-restricted network model was illustrated with a directed example network. The model was also applied to a portion of the Southwest Freeway corridor in Houston. Comparisons of both the logic of the modeling concepts and the consistency of assignment and simulation results suggest that the nodal capacity-restricted dynamic network model is superior to the existing models for corridor traffic management applications.
Optimization of intersection signal parameters within equilibrium route choice models. Said, Kawkeb A. H., Ph.D. University of Illinois at Chicago, 1993. 227 pp. Order Number DA93-35147