## 3 Experiment
### Results and Discussion
#### 3.2.2 Vehicle Detection and Tracking
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Jaccard Coefficient of**} & \multicolumn{2}{c}{**Jaccard Coefficient of**} \\  & \multicolumn{2}{c}{**Oncoming Vehicles**} & \multicolumn{2}{c}{**Preceding Vehicles**} \\ \cline{2-5}
**Test Videos** & \multicolumn{2}{c}{**Without**} & \multicolumn{2}{c}{**With**} & \multicolumn{2}{c}{**Without**} & \multicolumn{2}{c}{**With**} \\  & **Occlusion** & **Occlusion** & **Occlusion** & **Occlusion** \\  & **Handling (\%)** & **Handling (\%)** & **Handling (\%)** & **Handling (\%)** \\ \hline Video 1 & 81.56 & 96.16 & 94.12 & 98.6 \\ Video 2 & 72.69 & 96 & 93.59 & 99.2 \\ Video 3 & 76.37 & 94.75 & 88.43 & 97.35 \\ Video 4 & 85.19 & 95.51 & 98.76 & 98.76 \\ Video 5 & 88.73 & 94.39 & 93.67 & 96.07 \\ Video 6 & 79.35 & 96.54 & 97.19 & 98 \\ Video 7 & 86.28 & 95.94 & 85.08 & 98.13 \\ Video 8 & 73.4 & 93.33 & 84.19 & 98.36 \\ Video 9 & 73.19 & 92.19 & 93.45 & 99.51 \\ Video 10 & 85.21 & 91.63 & 78.32 & 97.59 \\
**Average result** & **80.2** & **94.64** & **90.68** & **98.16** \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Vehicle detection results for test videos of two-lane urban roads. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Jaccard Coefficient of**} & \multicolumn{2}{c}{**Jaccard Coefficient of**} \\  & \multicolumn{2}{c}{**Oncoming Vehicles**} & \multicolumn{2}{c}{**Preceding Vehicles**} \\  & \multicolumn{2}{c}{**(Headlights)**} & \multicolumn{2}{c}{**(Tailllights)**} \\ \cline{2-5}
**Test Videos** & \multicolumn{2}{c}{**Without**} & \multicolumn{2}{c}{**With**} & \multicolumn{2}{c}{**Without**} & \multicolumn{2}{c}{**With**} \\  & **Occlusion** & **Occlusion** & **Occlusion** & **Occlusion** \\  & **Handling (\%)** & **Handling (\%)** & **Handling (\%)** & **Handling (\%)** \\ \hline Video 1 & 83.84 & 91.28 & 71.33 & 93.9 \\ Video 2 & 84.48 & 92.29 & 81.18 & 95.18 \\ Video 3 & 86.91 & 89.61 & 85.45 & 89.37 \\ Video 4 & 71.65 & 91.57 & 83.21 & 93.69 \\ Video  
Table 4 shows the average vehicle detection results for both two-lane and four-lane scenarios. With occlusion handling, the proposed method has enhanced the system performance effectively; the average detection result for preceding vehicles is 92.23% and that for oncoming vehicles is 95.81%. The results of vehicle detection based on headlights are lower than those for taillights, as the blooming effect frequently occurs for headlights. Because of that, the size, shape, and illuminance of headlights are unstable in the captured images. As a result, false pairing between adjacent vehicles occurs because a light in a vehicle may be paired with a light in another vehicle, especially in the four-lane scenario. Additionally, the detection results for the two-lane scenario are higher than those in the four-lane scenario, because many situations that can cause incorrect pairing occur in the four-lane scenario. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{3}{*}{**Scene**} & \multicolumn{2}{c}{**Jaccard Coefficient of**} & \multicolumn{2}{c}{**Jaccard Coefficient of**} \\  & \multicolumn{2}{c}{**Oncoming Vehicles**} & \multicolumn{2}{c}{**Preceding Vehicles**} \\  & \multicolumn{2}{c}{**(Headlights)**} & \multicolumn{2}{c}{**(Taillights)**} \\ \cline{2-5}  & **Without** & **With** & **Without** & **With** \\  & **Occlusion** & **Occlusion** & **Occlusion** & **Occlusion** \\  & **Handling (\%)** & **Handling (\%)** & **Handling (\%)** & **Handling (\%)** \\ \hline Two lanes & 80.2 & 94.64 & 90.68 & 98.16 \\ Four lanes & 77.61 & 89.82 & 80.09 & 94.41 \\
**Average result** & **78.9** & **92.23** & **85.39** & **95.81** \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Average vehicle detection results of two-lane and four-lane videos. Figure 16: Results of vehicle detection for vehicle occlusion: (**a,c**) without occlusion handling; (**b,d**) with occlusion handling. Figure 17: Results of vehicle detection in case of two vehicle lights detected as one light: (**a**) without occlusion handling; (**b**) with occlusion handling.