# Gazing Characteristics of a Driver during Vehicle Backing
## 3 Results
For S-V, there was no significant difference in the total gazing time of all AOIs between the start phase (6.24 s) and the stop phase (7.15 s). On the contrary, for BC-V, the total gazing time of all AOIs for the stop phase (13.12 s) was significantly longer than that for the start phase (6.79 s). Furthermore, for BCS-V, the total gazing time of all AOIs for the stop phase (11.89 s) was significantly longer than that for the start phase (6.37 s). The reason for the longer total gazing time of all AOIs for BC-V and BCS-V is possibly because of the use of a monitor in the vehicle with a backup camera. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Gaze Time for Start Phase (s)**} & \multicolumn{2}{c}{**Gaze Time for Stop Phase (s)**} & \multicolumn{1}{c}{\multirow{2}{*}{\(p\)**-Value**}} \\ \cline{2-2}
**AOI** & **Average** & **SD** & **Average** & **SD** & \\ \hline
1. No-tech vehicle (NT-V) & & & & & \\ \hline Rearview mirror & 0.33 & 0.50 & 0.10 & 0.29 & 0.161 \\ \hline Left-side mirror & 5.57 & 2.80 & 2.32 & 2.29 & 0.002 ** \\ \hline Right-side mirror & 0.78 & 0.86 & 5.06 & 3.08 & \textless{0.001 **} \\ \hline Total of all AOIs & 6.67 & 2.99 & 7.48 & 4.47 & 0.580 \\ \hline
2. Sonar vehicle (S-V) & & & & & \\ \hline Rearview mirror & 0.21 & 0.31 & 0.04 & 0.14 & 0.080 \\ \hline Left-side mirror & 5.49 & 2.39 & 2.54 & 2.36 & 0.003 ** \\ \hline Right-side mirror & 0.54 & 0.67 & 4.57 & 2.97 & \textless{0.001 **} \\ \hline Total of all AOIs & 6.24 & 2.66 & 7.15 & 3.81 & 0.469 \\ \hline
3. Backup-camera vehicle (BC-V) & & & & & \\ \hline Monitor & 2.89 & 3.08 & 9.70 & 4.44 & \textless{0.001 **} \\ \hline Rearview mirror & 0.03 & 0.08 & 0.00 & 0.00 & - \\ \hline Left-side mirror & 3.37 & 2.74 & 1.10 & 1.37 & 0.145 \\ \hline Right-side mirror & 0.49 & 0.57 & 2.32 & 1.95 & 0.004 ** \\ \hline Total of all AOIs & 6.79 & 3.03 & 13.12 & 4.35 & \textless{0.001 **} \\ \hline
4. Backup-camera with sonar vehicle (BCS-V) & & & & & \\ \hline Monitor & 2.15 & 2.14 & 8.44 & 3.35 & \textless{0.001 **} \\ \hline Rearview mirror & 0.07 & 0.24 & 0.01 & 0.04 & 0.353 \\ \hline Left-side mirror & 3.85 & 2.46 & 1.31 & 1.53 & 0.003 ** \\ \hline Right-side mirror & 0.30 & 0.39 & 2.13 & 1.54 & 0.001 ** \\ \hline Total of all AOIs & 6.37 & 2.85 & 11.89 & 3.10 & \textless{0.001 **} \\ \hline \hline \end{tabular} Note: **\(p\)**-Value \(<\) 0.01. The unpaired \(t\)-test was conducted to determine the significant difference. Number of all volunteers: 14.  
\end{table} 
Table 1: Significant difference in the average gazing time of all volunteers in each AOI in a given technology between the start phase and stop phase. Figure 7: Gazing time ratio of individual AOIs compared to all AOIs: (**a**) Start phase; (**b**) Stop phase. Table 2 presents the significant difference in the AOI usage rate in each technology between the start and stop phases. For NT-V, all the drivers used the left-side mirror in both the phases. The rate of using the right-side mirror for the stop phase (93%) was higher than that for the start phase (64%). However, there was no significant difference between them (93% and 64%); the p-value was close to the 5% level (\(p\) = 0.065). For S-V, most of the drivers used the left-side mirror in the start phase (100%) and stop phase (93%). The rate of using the right-side mirror for the stop phase (100%) was significantly higher than that for the start phase (57%). For BC-V, the rate of using the monitor for the stop phase (100%) was significantly higher than that for the start phase (57%). The rate of using each mirror was not significantly different in the two phases. For BCS-V, the rate of using a monitor for the stop phase (100%) was higher than that for the start phase (79%). However, no significant difference was observed between them (100% and 79%); the p-value was also close to the 5% level (\(p\) = 0.067). The rate of using the right-side mirror for the stop phase (93%) was significantly higher than that for the start phase (57%).