## 1 Introduction  
Monitoring of traffic is usually done using conventional methods by traffic cameras. This approach requires static fixed cameras and existing infrastructure, which may not only be cost-ineffective but also ineffective in situations where temporary monitoring is required. With the recent advancements in technology, Unmanned Aerial Vehicles (UAVs) may provide a solution to this problem. UAVs have become popular in recent years. Such devices bid a wide range of applications that include aerial photography, cinematography, express shipping and delivery, and monitoring of surroundings. Nowadays, applications of UAVs tend to move to the next level and make them intelligent and autonomous as well. The field of computer vision is essential for the utilization of UAVs in cities to gain beneficial information from the real world. The purpose of this research is to investigate the possible situation in traffic monitoring using UAVs and design a system that provides information on the number of vehicles, their visual representation, and estimates of their direction. Specifically, the research described in this paper proposes and experimentally implements a web-based service for traffic environment monitoring, specifically its flow and load. Once information from the video is extracted, we will be able to estimate the number of cars that utilize the road in specific time intervals and also their direction. Such data can be used as the input for the _Sloak Road Administration_; until now, such a process is being done manually. The proposed web application offers a variety of personalized services that include a user profile, in which all data are stored, device-independent and free access, and a minimum hardware load of the user's device. The same holds for the UAVs; they are becoming common to use mobile web applications (e.g., online visualization of data in research by [PERSON] et al. [1]), solutions for the processing of imagery from UAVs in research by [PERSON] [2] of their employment to ensure safety in transportation (research by [PERSON], [PERSON] [3], or by [PERSON] et al. [4]). The experimental web-based solution may automatically estimate a specific category, which may include humans, cars, or other objects. The subsequent step is a visualization of the detection results accessible to the user. The primary input element to the proposed system is a video in a specific format captured by a UAV. Input to the system may also be from other sources, e.g., surveillance cameras. The principal idea is to use a portable surveillance device to monitor the traffic from a certain view and obtain as much data from the real environment as possible. The purpose of this research is to propose an experimental solution for the monitoring of traffic from the perspective of a UAV. In the sections below, the algorithms are analyzed for object detection, and, based on this, the design of the experimental software solution is created, which is then experimentally verified. The contribution of this work may be summarized as follows:  
* Assessment of the UAV's potential to monitor the temporal state of the traffic in multiple locations and determine the suitable scenarios;
* Design and implement the experimental software solution for the detection of vehicles, estimation of their number, and direction;
* Verify the algorithms for video analysis following sample scenarios. The idea behind the monitoring of the traffic using UAV may bring several advantages compared to a static traffic monitoring solution. Rather, complex installation is not required, monitoring of traffic from multiple locations in specific day intervals may be achieved, or variable environments that contain vehicles may be monitored at any time during the day. The utilization of UAVs may also bring difficulties, starting with changing weather conditions. Strong winds or rain may not only deviate from the tracking of the vehicles but render it completely unusable.