A case study of Zurich’s two-layered perimeter control

This paper evaluates Zurich’s perimeter control with loop detector data from the entire city. We compare the speed indices and congestion levels within the controlled area and its surrounding areas using the concept of the macroscopic fundamental diagram (MFD). At times of heavy congestion, vehicles are prevented by two layers of control to enter the perimeter of the inner city. With the introduction of the concept of the MFD and the control derived thereof, Zurich’s perimeter control has received some academic attention, however, an analysis of its performance has not been reported. We find evidence that the perimeter control, which is primarily informed by the flow levels, performs well – even though such a flow-based perimeter control has not been popular with academics so far.