# Mitigating Urban Congestion: A Cooperative Reservation Framework for Automated Vehicles
## 7 Experimentation and Results
### Scenario 1--Intersection  
In Figure 8, the proposed scenario to test the basic functionalities explained in previous sections can be seen (high-definition enlarged figures can be seen in [56]). This particular experiment focuses on the arbitration of each Cooperative Connected Automated Vehicle when approaching the intelligent intersection. In this case, the system implements the arbitration methodology with the ETA optimization explained in Section 6. In Figure 8a, the top-down view display of the ROS visualizer (Rviz) can be seen together with the _Road Plan_ (Blue and Green lanes), planned ABPs (Orange Circles), and HD Map information (red arrows and landmarks with black digits). On the other hand, in Figure 8b, the odometry readings for each vehicle recorded during the experimentation are depicted. This odometry comes from the vehicle container localization system based on a Kalman Filter for filtered positioning [46] using the GNSS and IMU sensors. The expected result of this specific scenario is an automatic management of the Cooperative Connected Automated Vehicles converging with the intersection at similar times. In Figure 9, the behavior signals activated during the arbitration process, as well as the speed of each CCAV, can be seen. As can be seen, once a connection to the intersection arbitration system is performed, each of the connected vehicles is assigned a _Cluster_ and updated with a custom behavior deployed in each local mission that adjusts the vehicle with local procedures on how to operate inside the intersection. This behavior would be different depending on the compatibility between the _Clusters_ assigned and the time predicted for each vehicle to reach the conflict zone tested between each _Tracking Node Cluster_. Therefore, each mission will be updated with Entry and/or Exit ABPs in order to arbitrate the entrance between vehicles. Furthermore, since the vehicle's mission is being tracked, the arbitration system is able to know if the vehicle is approaching or waiting for entrance and if it has already been arbitrated or not. Since this experiment consists of four vehicles converging into the intersection at a similar time, the arbitration system must manage the conflict zones between incoming vehicles to properly give entrance depending on _Cluster_ compatibility. On the one hand, in Figure 9d, Vehicle 3 was requested to stop by adding an Entry \(ABP\) to its Mission. On the other hand, the remaining vehicles, shown in Figure 9a-c, are given free access since the intersection resources are compatible. While the speed of those with free access is maintained, it gradually decreases for Vehicle 3. Then, it is not until the conflict zones are free that the arbitration system releases the waiting flag, effectively allowing entrance to the intersection. Figure 8: Intersection scenario with 4 Cooperative Connected Automated Vehicles. In Figure 10, the configuration found in the Carla Server for the intersection arbitration can be seen with the interaction between Cooperative Connected Automated Vehicles and the intelligent Intersection managed. Figure 10a represents the initial stage of the arbitration, where the vehicles were approximating the intersection, and then Figure 10b,c depict how some vehicles are marked for entrance and others for stopping. Finally, Figure 10d represents the final stage of  
Figure 10: Cooperative Connected Automated Vehicles approaching the intersection in the Carla Simulator. Figure 9: Cooperative Connected Automated Vehicle signals approaching the intersection. the arbitration process, where the waiting vehicle in this case is given free entrance after the other vehicles leave their respective conflict zones. Once every vehicle leaves the intersection, the tracking process stops and waits for new incoming request connections. Note the Exit _ABPs_ placed by the _Intersection Manager_ to release the resource usage once the tracked vehicle leaves.