City-wide traffic control: Modeling impacts of cordon queues

Optimal cordon-metering rates are obtained using Macroscopic Fundamental Diagrams (MFD) in combination with flow conservation laws. A model-predictive control algorithm is also used so that time-varying metering rates are generated based on their forecasted impacts. The authors' scalable algorithm can do this for an arbitrary number of cordoned neighborhoods within a city. Unlike its predecessors, the proposed model accounts for the time-varying constraining effects that cordon queues impose on a neighborhood’s circulating traffic, as those queues expand and recede over time. The model does so at every time step by approximating a neighborhood’s street space occupied by cordon queues, and re-scaling the MFD to describe the state of circulating traffic that results. The model also differentiates between saturated and under-saturated cordon-metering operations. Computer simulations of an idealized network show that these enhancements can substantially improve the predictions of both, the trip completion rates in a neighborhood and the rates that vehicles cross metered cordons. Optimal metering policies generated as a result are similarly shown to do a better job in reducing the Vehicle Hours Traveled on the network. The vehicle hours of travel (VHT) reductions stemming from the proposed model and from its predecessors differed by as much as 14%.


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  • Accession Number: 01705947
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 22 2019 3:05PM