## 3 Research Model and Methodology  
### Research Model  
This research aims to investigate the relationship between the independent variable and the dependent variables that are summarized in Table 1 and serve as key indicators for understanding driver behavior within roundabouts. By exploring these variables, the study seeks to gain a vision into the impact of junction control on driver actions and ultimately contributes to enhancing traffic flow efficiency and safety in roundabouts. The case study choice in this research paper is crucial as it focuses on investigating driver behaviors in signalized and non-signalized roundabouts in Qatar. This selection allows for a detailed examination of how drivers interact with roundabouts in a specific context characterized by unique traffic conditions, cultural factors, and rapid urban development. The methodological model employed in this study, including the use of nonparametric statistical methods, can be replicated in other regions with similar traffic conditions to generate comparable insights and recommendations. \begin{table}
\begin{tabular}{c c} \hline \hline
**Independent Variable** & **Dependent Variables** \\ \hline Junction Control (Signalized & Lane Change \\ and Non-Signalized) & Correct Lane Usage (Entering/Exiting) \\  & Turn Signal Usage (Entering/Exiting) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The following table defines the variables for this research. Lane change refers to the action of vehicles changing lanes or switching from one lane to another while navigating inside a roundabout, which is illustrated in Figure 1. It measures the frequency and occurrence of lane changes made by drivers as they move through the circular intersection. This variable provides insight into driver behavior and decision-making during roundabout traversal. Lane changes can help drivers select the most suitable lane for their desired exit or accommodate varying traffic conditions. However, excessive or improper lane changes can disrupt the flow of traffic and increase the risk of accidents. Correct lane usage refers to the extent to which drivers adhere to the designated lanes while navigating a roundabout, which is demonstrated in Figure 2. It assesses whether drivers choose and stay in the appropriate lane as they approach, circulate within, and exit the roundabout. Correct lane usage is an important measure of driver compliance with roundabout rules and contributes to the safe and efficient operation of the intersection. The concept of correct lane usage is based on the prescribed lane assignments in a roundabout, which are typically marked with pavement markings, signs, or other lane indicators. Each lane within the roundabout is designated for a specific exit or a specific direction of travel. Drivers should enter the roundabout using the appropriate entry lane and then choose and maintain the correct lane that aligns with their intended destination or travel path. Generally, the right lane is typically used for vehicles intending to take the first exit or continue straight, the middle lane is often for vehicles going straight or taking the second exit, and the left lane is used for vehicles preparing to take the second exit or to make a U-turn. Upon reaching the roundabout, the driver must yield to circulating traffic and use turn signals if a lane change is necessary before entry. Once inside, the driver should maintain their designated lane without unnecessary lane changes to avoid conflicts with other vehicles. When preparing to exit, the driver must signal in advance and ensure they are in the correct lane. Typically, vehicles in the right lane can exit directly, while those in the left lane must merge right before exiting safely. The turn signal usage variable indicates the use of turn signals by drivers while maneuvering through a roundabout, which is illustrated in Figure 3. It measures the frequency and consistency with which drivers indicate their intention to change lanes or exit the roundabout by activating their vehicle's turn signals.