Abstract
Several studies indicate that rural traffic flow can most accurately be modelled in terms of travelling queues of vehicles. We consider the second order statistical properties (variance, autocorrelation function, and spectral density) of the acoustic noise generated by such streams of traffic. Calculations are given for a mode in which the headway distribution within a queue differs from that between successive queues. We show that changes inflow rate are more important for determining second order properties than are details of the within queues headway distribution.