Traffic signal coordination in over-saturated traffic scenarios

Abstract

Nowadays, various types of traffic control strategies are appearing to alleviate the problem of traffic congestion. With the aim of minimise the traffic volume contained for over-saturated scenarios, a traffic-responsive control strategy is developed based on the concept of the cell transmission model. The control strategy takes into consideration the nonlinear relationship between traffic flow, traffic capacity and corresponding traffic signals for each road segment in the traffic network. Traffic-responsive signal coordination methodology is studied and transformed into a mixed-integer linear programming problem solved by CPLEX optimization tool in Matlab environment. In order to observe the performance of the proposed traffic signal controller, a fixed-time traffic signal model is constructed with predefined signal inputs in Matlab. Traffic boundary inflow entering into both traffic models for each prediction horizon is synchronized. Both models are simulated with multiple traffic network scales. The behaviour of the two types of traffic models is observed and analysed accordingly. The validity and performance of the proposed traffic signal coordination strategy for the tested cases are evaluated against the fixed-time traffic signal model. Further recommendations on the proposed control approach are addressed at the end of the report.