In order to analyze the concept of network (node) efficiency we offer a mathematical model for identifying choke points.
The underlying theory is based on the relationship between link flow and time interval. We will focus on analyzing network
conditions beyond the equilibrium state (i.e. when the network begins to disintegrate and becomes less reliable). If flow a link flow qa, over the time interval t0 (this can be selected based on industry practice for data collection) is to pass through a node N, the arrival rate ba over that time interval is given by,
Where, = Initial link free flow per unit time = incidental change in link flow due to additional system loading within
interval .