# Assessing Traffic-Flow Safety at Various Levels of Autonomous-Vehicle Market Penetration
## 4 Results
### Traffic Safety Analysis Results
#### 4.2.2 Conflict Risk Analysis  
Conflict risk analysis analyzes how dangerous each case is, and in this study, we analyzed the risk level according to the TTC value. As detailed in Table 7, the results of analyzing the number of conflicts between autonomous vehicles and conventional vehicles by conflict risk level showed that conflicts with conflict risk level 1 accounted for about 50.5-100.0% of the total number of conflicts per case in all cases, indicating a very high probability of accidents. In addition, the number of conflicts with conflict risk level 1 decreased steadily as the adoption rate of autonomous vehicles increased after 20%.  
As shown in Table 8, when analyzing the number of conflicts between autonomous vehicles and conventional vehicles by conflict risk level, it was found that conflicts with conflict risk level 1 accounted for approximately 49.4 to 93.3% of the total number of conflicts per case in all cases. In addition, when analyzing the number of conflicts with conflict risk level 1, it was found that the number of conflicts with conflict risk level 1 increased steadily until the adoption rate of autonomous vehicles increased to 30%, in contrast to the results of the analysis of conflicts between conventional vehicles.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Case**} & \multicolumn{3}{c}{**HDV-HDV Conflicts**} & \multicolumn{3}{c}{**HDV-AV Conflicts**} & \multicolumn{3}{c}{**Total**} \\ \cline{2-13}  & \multirow{2}{*}{**Side**} & \multirow{2}{*}{**Rear**} & \multirow{2}{*}{**Sum**} & \multicolumn{3}{c}{**HDV-AV**} & \multicolumn{3}{c}{**AV-HDV**} & \multirow{2}{*}{**Sum**} & \multirow{2}{*}{**Side**} & \multirow{2}{*}{**Rear**} & \multirow{2}{*}{**Sum**} \\ \cline{3-3} \cline{5-13}  & & & & **Side** & & & & & & & & \\ \hline MPR 10\% & 55.4 & 113.8 & 169.2 & 0.8 & 4.6 & 5.4 & 43.6 & 49.0 & 99.8 & 118.4 & 218.2 \\ MPR 20\% & 137.8 & 541.6 & 679.4 & 19.2 & 129.2 & 148.4 & 36.8 & 185.2 & 193.8 & 670.8 & 864.6 \\ MPR 30\% & 57.6 & 81.0 & 138.6 & 7.4 & 19.0 & 26.4 & 174.0 & 200.4 & 239.0 & 100.0 & 339.0 \\ MPR 40\% & 3.4 & 42.8 & 46.2 & 1.2 & 21.8 & 23.0 & 48.6 & 71.6 & 53.2 & 64.6 & 117.8 \\ MPR 50\% & 2.2 & 35.0 & 37.2 & 0.8 & 24.6 & 25.4 & 32.2 & 57.6 & 35.2 & 59.6 & 94.8 \\ MPR 60\% & 0.2 & 17.6 & 17.8 & 0.2 & 27.2 & 27.4 & 11.6 & 39.0 & 12.0 & 44.8 & 56.8 \\ MPR 70\% & 0.2 & 11.2 & 11.4 & 0.0 & 22.2 & 22.2 & 7.4 & 29.6 & 7.6 & 33.4 & 41.0 \\ MPR 80\% & 0.0 & 5.2 & 5.2 & 0.0 & 17.4 & 17.4 & 3.6 & 21.0 & 3.6 & 22.6 & 26.2 \\ MPR 90\% & 0.0 & 2.0 & 2.0 & 0.0 & 10.4 & 10.4 & 1.2 & 11.6 & 1.2 & 12.4 & 13.6 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Number of conflicts by case (unit: times).  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Case**} & \multicolumn{3}{c}{**Side Collision**} & \multicolumn{3}{c}{**Rear Collision**} & \multicolumn{3}{c}{**Total**} \\ \cline{2-13}  & **TTC 1** & **TTC 2** & **TTC 3** & **TTC4** & **TTC 1** & **TTC 2** & **TTC 3** & **TTC4** & **TTC 1** & **TTC 2** & **TTC 3** & **TTC4** \\ \hline MPR 10\% & 45.4 & 4.6 & 4.2 & 1.2 & 105.4 & 3.0 & 2.8 & 2.6 & 150.8 & 7.6 & 7.0 & 3.8 \\ MPR 20\% & 80.6 & 21.4 & 22.8 & 13.0 & 262.6 & 35.4 & 85.6 & 158.0 & 343.2 & 56.8 & 108.4 & 171.0 \\ MPR 30\% & 42.8 & 6.2 & 5.8 & 2.8 & 72.8 & 1.8 & 4.6 & 1.8 & 115.6 & 8.0 & 10.4 & 4.6 \\ MPR 40\% & 2.0 & 0.6 & 0.4 & 0.4 & 38.6 & 1.0 & 0.6 & 2.6 & 40.6 & 1.6 & 1.0 & 3.0 \\ MPR 50\% & 1.4 & 0.4 & 0.2 & 0.2 & 31.8 & 1.2 & 1.4 & 0.6 & 33.2 & 1.6 & 1.6 & 0.8 \\ MPR 60\% & 0.2 & 0.0 & 0.0 & 0.0 & 16.6 & 0.6 & 0.2 & 0.2 & 16.8 & 0.6 & 0.2 & 0.2 \\ MPR 70\% & 0.0 & 0.2 & 0.0 & 0.0 & 10.2 & 0.4 & 0.2 & 0.4 & 10.2 & 0.6 & 0.2 & 0.4 \\ MPR 80\% & 0.0 & 0.0 & 0.0 & 0.0 & 4.8 & 0.0 & 0.2 & 0.2 & 4.8 & 0.0 & 0.2 & 0.2 \\ MPR 90\% & 0.0 & 0.0 & 0.0 & 0.0 & 2.0 & 0.0 & 0.0 & 0.0 & 2.0 & 0.0 & 0.0 & 0.0 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Conflict risk analysis results by case (HDV-HDV) (unit: times).