Acquiring and processing video streams from static cameras has been proposed as one of the most green equipment for visualizing and amassing traffic statistics. With the today's advances in technology and visual media, combined with the multiplied desires in managing congestion extra correctly and immediately, using Unmanned Aerial Aircraft Systems (UAS) has emerged in the subject of site visitors engineering. In this paper, we evaluate research and applications that comprise UAS in transportation research and practice with the purpose to set the grounds from the right information and implementation of UAS related surveillance systems in transportation and visitors engineering. The research reviewed are classified in exclusive transportation engineering areas. Additional substantial programs from other research fields are also referenced to pick out different promising packages. Finally, troubles and emerging demanding situations in each a conceptual and methodological level are discovered and mentioned.