Traffic management plays an important role in the smart city concept, enabling the authorities to observe and control the traffic flow. The key elements of such system are the sensing nodes, which provide information regarding the speed of each individual vehicle. Current speed measurement devices use separate sensors for speed estimation (RADAR/LIDAR), and vehicle identification (camera). These are expensive devices, and thus not suitable for example, to monitor the whole road network of a city, which would require a large number of sensing nodes.