# Emerging Decision-Making for Transportation Safety: Collaborative Agent Performance Analysis
## 4 Simulation Analysis and Validation
### Observations of Emergent Behaviour--_Highway Ramp Merging_  
After the system and agents have been defined, the model can be executed to observe what actions transpire, their cause, and what it means. Several scenarios are simulated to understand how and when the agents decide to react and what its effect would have on the environment. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Category** & **Parameter** & **Description** & **Value** \\ \hline \multirow{8}{*}{Traffic Conditions} & \multirow{4}{*}{Density} & It defines the no. of vehicles in the simulated segment of the road. & \multirow{2}{*}{10} \\  & & This the velocity of the vehicle. & & \\ \cline{2-3}  & \multirow{2}{*}{Flow Rate} & This is the rate at which the vehicles pass through a particular point on the road. & \multirow{2}{*}{Low} \\ \cline{2-3}  & & These include vehicle parameters such as acceleration and steering. & & \\ \cline{2-3}  & \multirow{2}{*}{Road Geometry} & This represents characteristics of the road such as lane width, slope, and curvature, which influence vehicle movement. & \multirow{2}{*}{5 m/s\({}^{2}\)} \\ \cline{2-3}  & \multirow{2}{*}{Lane Markings} & Dividers that separate lanes and guide vehicle movement. They can include solid lines, dashed lines, and arrows indicating directions. & \multirow{2}{*}{Dashed lines.} \\ \cline{2-3}  & \multirow{2}{*}{Intersection Types} & Elements that define how vehicles interact at intersections, such as stop signs, yield signs, traffic lights, and roundabouts. & \multirow{2}{*}{N/A} \\ \cline{2-3}  & \multirow{2}{*}{Obstacles} & Objects or conditions on the road that affect vehicle movement, such as parked cars, pedestrians, construction zones, and adverse weather conditions. & \multirow{2}{*}{N/A} \\ \cline{2-3}  & & & \\ \hline \end{tabular}
\end{table} 
Table 6: Simulated traffic parameters. Figure 10: Architecture of basic driver strategy to check if it is safe to change lanes. For lane switch cases, the most prominent responses as the vehicle are either trying to force itself into the next lane, as seen in Figure 11, or remain at its current acceleration until it finds another safe opportunity, as seen in Figure 11. We observe in some cases that there is little space between itself and the front vehicle. Comparing two-lane switches to three-lane cases highlights the evolution of behaviour in response to simply incorporating another lane. Whereas in former examples we witness either a lane change or no action taken, for the latter, we witness how two vehicles begin to initiate a manoeuvre into the same middle lane as shown in Figure 12a, forcing one agent to rescid its decision and return to its original, safer position, as seen in Figure 12b. Not only does this illustrate how applying checks only to the adjacent lanes limits what can be predicted, but it also demonstrates the behaviour's quick response to divert the AV back to safety. Despite not resulting in any hazards, this is still a risky situation as it has forced evasive action from the AV that can be detrimental to the environment in the form of car accidents or collisions. Although the behaviour is adapting to its surroundings, and can effectively prevent major incidents occurring, the range of the sensors and the scope of the checks are not sufficient to ensure emergency actions do not occur as regularly as they did. This would be improved by further developing the behaviour to perform more vigorous checks and tests, broadening the scope of what can be measured, to confidently determine that no risks will be incurred from its actions. For merge cases, we witness either a manoeuvre into the main carriageway, as seen in Figure 13a,b, or a deceleration to adjust itself within its current lane to not collide with any oncoming traffic, shown in Figure 14a. The latter is due to environmental limitations because if the AV deems it unsafe to merge, it does not have the road space to continue cruising in its current lane at its current speed and must respond by decelerating to prevent collisions.