TRAFFIC FLOW CONTROL

HOMOLOVÁ, J.

Abstract

The paper introduces a new concept of the hierarchical regulator of the traffic flow. This regulator has two control levels: (i) the local control of micro-regions and (ii) the coordination of whole traffic region consisting of several micro-regions. His aim is to derive the optimal signal setting of the traffic lights with respect to actual traffic conditions. This is the only way how to ensure conditions of more continuous transit through the region. The state space model of micro-region is based on a maximum utilization of available information from all measured traffic variables and it estimates lengths of queues formed on arms of junctions with traffic lights. The queues are modeled according to hydrodynamic analogy and their values are corrected by Kalman filtering in case of defects or measurement inadequacy. The model for coordination level is derived analogically. Control variables are relative green signals for all junctions included. Both models and all variable restrictions are linear and this fact allows us, on condition of linear criterion, to use the linear programming as the optimization tool. For this reason, the criterion minimizes the sum of the weighted queue lengths. The model and control strategy efficiency is demonstrated by several experiments.

Coresponding author e-mail: jkratoch[at]utia[dot]cas[dot]cz

Session: Applications and Case Studies