Traffic flows surveying and monitoring by drone-video

For the purposes of planning and managing mobility phenomena, the traffic detection is a widespread practice. In particular, automatic measurements of vehicular traffic on road sections are operated by electronic equipment and different sensors. Some technologies, included in the general class of traffic analysers, also allow to detect other parameters such as vehicle dimension, speed, spacing, headway. Generally, these are most interesting tools for the classification and characterisation of vehicles, but also more expensive and imply expensive work on the road. The paper proposes a short state of the art concerning traffic detection systems with a particular focus on Unmanned aerial systems (UAS). Some experimental results are proposed referring to surveys conducted with the help of drones. The surveys refer to three different contexts: an urban road section, an urban road intersection, a freight terminal. The focus is in particular on the measurement of flow parameters such as flow, density, speed and the classification of vehicles in predefined categories. Moreover, some considerations emerged from the experimental analyses, on the applicative potential of the UAS and on the perspectives for the development of the technological characteristics of these instruments.