## 2 Materials and Methods
### Traffic Knowledge Module  
This module was developed to test users' knowledge about traffic safety. It consists of two submodules. The first module tests students' knowledge regarding traffic rules, i.e., traffic signs, symbols etc. The main aim is to test the participants' traffic knowledge based on ten questions. Also, feedback is provided immediately after participants answer the question, where additional explanation is given about the correct answer. Similarly, the second submodule consists of two parts. Firstly, the participants were presented with a podcast on hand-free calling, in which a traffic safety expert is being interviewed. After the podcast was finished, ten questions were asked about the podcast. Therefore, the participants must listen to the podcast carefully to answer those questions. Situation Awareness Module  
This module was a new addition to the online platform as it was made based on 360\({}^{\circ}\) images. It consists of a module with ten questions about different traffic scenarios. Thanks to 360\({}^{\circ}\) images, the participants had the liberty to rotate the image left and right to view the entire environment. The feedback after each question was also displayed with an additional explanation of the answer. The feedback improved the participants' understanding of different traffic situations. This module was developed to check the skills of risk detection among the participants. It also consists of three sub-modules. The first submodule, entitled \"Find the danger\", aims to test the risk detection of participants. The participants were shown ten images to ask where they should pay attention first. After each question, the feedback was provided with a detailed explanation of the risk in the given image. Similarly, the second submodule, entitled \"Traffic in Everyday Life,\" aimed to search for traffic violations in different video clips. Feedback was also provided after each question to make the participants understand the traffic violations. Moreover, the third sub-module was a new addition to the platform as the drone was added. This module's main aim was to assess participants' ability to detect risk behaviors or irregularities of other road users. It has two types of questions. Firstly, the video clip was shown to the participants, and they had to identify where the traffic violation took place. The drone was placed at a certain height where the participants could overview the entire traffic situation. A specific box was added in the video for the second type of question. The participants intended to look at the situation within the box and answer the question after the finished video. As mentioned above, feedback was provided after every question to provide a better understanding of the situation. Figure 1 illustrates examples of the risk detection questions, showing both the general traffic scene and the version with a highlighted focus box. These visual aids supported participants in identifying traffic violations or risks with greater precision. Risk Management Module  
This module was similar to risk management, where different traffic safety scenarios were shown in the images, and participants had to answer them correctly. This module is intended for the participants to indicate the best possible behavior to exhibit. The ten multiple-choice questions were asked with an image to visualize the situation. After each question, detailed feedback was provided so the participants knew about different traffic risk situations and acted accordingly. Figure 1: Aerial traffic scenario from the R2S platform. **Left**: “Where do you see a traffic violation?” **Right**: Focused view within the orange rectangle. This module was innovative compared to other traffic education initiatives because the VR technology was used. No joystick or VR glasses were used to make it friendlier and more economical. The participants can navigate and look right and left using the arrows on the keyboard.