Abstract: There is described a method of estimating one or more properties of traffic passing along segments of a road network, the traffic comprising a plurality of vehicles. The method comprises receiving, from a radio navigation receiver located at each vehicle of a subset of the vehicles, one or more first properties of each of those vehicles. The method also comprises using distributed acoustic sensing to generate, as a function of time and of position along a subset of the segments of the road network, signals representing acoustic vibration caused by the traffic at one or more sensing optical fibres that extend along the subset of segments.

Abstract: Methods and apparatus for estimating a position of a boundary of a queue of traffic are disclosed, the queue extending along a roadway. Distributed acoustic sensing is used to generate, as a function of time and of position along the roadway, a signal representing acoustic vibration at a sensing optical fibre that extends along the roadway. A queue signature is detected in the signal of either the slowing down of a plurality of vehicles as they approach the boundary of the queue, or speeding up of a plurality of vehicles as they advance from the departed boundary of the queue. A position of the boundary of the queue is then estimated from the detected queue signature.