# Data-Driven Test Scenario Generation for Cooperative Maneuver Planning on Highways
## 3 Results
### Scenario Catalog  
The described simulations are performed with all scenarios extracted from the data set. The result is a list of scenarios, each rated by the maximum drawback of all involved vehicles and the overall costs of the solutions of the reference and the cooperative planner. The decision as to which scenario should be part of the test catalog is made according to the quality criteria of validity and practicability described in Section 2.1. From the perspective of validity, a scenario is cooperative if at least one vehicle accepts a drawback in the cooperative solution in comparison to the standard behavior of the reference planner with the goal of reducing the overall scenario costs. In order not to classify negligible drawbacks as a cooperative action, a threshold is introduced. The value of this threshold is set equal to the costs of a lane change (0.1), which is considered the smallest clearly cooperative action. In addition to the requirement of an individual drawback, the cooperative solution of a valid test scenario must cause lower costs than the solution with the reference behavior. However, according to the concept of practicability described in Section 2.1, we consider a scenario only as relevant if the overall cost benefit of the cooperative solution is at least equal to the individual drawback of the cooperating vehicle. All scenarios that fulfill these requirements are regarded as valid and practically relevant and are therefore included in the test catalog.  
Table 2 illustrates the number of scenarios, the evaluated recording time, and the average cooperation costs of both behavior models for each roadway characteristic. Due to the varying recorded time, the number of extracted scenarios varies between 16 for the three-lane merge scenario and 1902 for the three-lane scenario. The average cooperation costs also differ in terms of roadway characteristics. With the reduction from 3 to 2 lanes, the average costs for both behavior models increase by 75 %. For the merge scenario, the average costs raise by a factor of 7 compared to the three-lane scenario without a merge lane. In terms of all roadway characteristics, the reference behavior model shows considerably higher costs (factors 2-3) compared with the fully cooperative behavior model. It is expected that behavior models that use cooperative maneuver planning, but are not capable of controlling all vehicles in a scenario, will fall between the performance of the fully cooperative and the reference planner.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Roadway** & **Number of Scenarios** & **Recording Time** & **Score Ref. Model** & **Score Coop. Model** \\ \hline Two-lane & 337 & 192 min & 1.80 & 0.84 \\ Three-lane & 1902 & 759 min & 1.04 & 0.48 \\ Three- and acc. lane & 16 & 30 min & 7.52 & 2.73 \\ Overall & 2255 & 981 min & 1.20 & 0.55 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Structure of the test scenario catalog.  
Figure 6: Longitudinal plot of the global planner.  
The selected scenarios cover the full speed range of uncongested highway traffic (Table 3). Differences between the solutions of the behavior models are particularly apparent in the minimum velocity, which drops to \(0\,\mathrm{m}\,\mathrm{s}^{-1}\) in the reference model, but is at least \(12.8\,\mathrm{m}\,\mathrm{s}^{-1}\) in the cooperative model. The range of acceleration shows that the cooperative model manages to solve the selected scenarios with common longitudinal driving behavior, whereas the reference model needs to perform hard braking maneuvers. Both minimum velocity and acceleration occur on ending lanes after unsuccessful merging maneuvers.