# An Analysis of Vulnerable Road Users Overtaking Maneuver along the Urban Road
## 3 Results
### Effects of Different Factors on Driver Behavior  
#### 3.3.1 Lane Width  
Each driver had 48 samples in total and 24 samples/types of lane width. So that, there were 48, 168, 144, 72 samples/types of lane width for type A, type B, type C, and type D, respectively.  
The Repeated Measures ANOVA tests on LPG revealed a significant effect of lane width for type A, type B and type D drivers, F(1,34) = 30.411, \(p\) < 0.0001, \(\eta^{2}_{\rm G}\) = 0.092; F(1,137) = 31.48, \(p\) < 0.0001, \(\eta^{2}_{\rm G}\) = 0.044; F(1,71) = 31.78, \(p\) < 0.0001, \(\eta^{2}_{\rm G}\) = 0.116, respectively. TukeyHSD tests showed statistically significant difference between LPG on 3.0 m lane width and 3.5 m lane width, with estimate values were \(-\)0.408 m (standard error SE = 0.12), \(-\)0.159 m (SE = 0.043), \(-\)0.233 m (SE = 0.054), respectively (Table 4). The tests with type C drivers disclosed no statistically significant effect of lane width F(1,131) = 0.819, \(p\) > 0.05.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Fixed**} & \multicolumn{5}{c}{**LPG**} & \multicolumn{5}{c}{**RMS**} \\ \cline{2-9}  & **Type A** & **Type B** & **Type C** & **Type D** & **Type A** & **Type B** & **Type C** & **Type D** \\ \hline LW:Is:T.L & - & - & - & - & - & - & - & - \\ \hline LW:Is:T. & - & - & - & - & ** & - & - & - \\ \hline LW:T.L & - & - & - & - & - & - & - & - \\ \hline LW:Is:L & - & - & - & - & - & - & - & - \\ \hline Is:T.L & - & - & - & - & - & - & - & - \\ \hline LW:Is & *** & * & - & - & *** & - & *** & - \\ \hline T.L & - & - & - & * & - & * & - & - \\ \hline LW:T & - & - & - & - & - & - & - & - \\ \hline Is:L & - & - & - & - & - & - & - & - \\ \hline LW:L & - & - & - & - & - & - & - & - \\ \hline Is:T & - & - & - & - & ** & - & - & - \\ \hline \hline \end{tabular} Significance sign: (-) \(p\) > 0.05; (*) \(p\) < 0.05; (**) \(p\) < 0.01; (**) \(p\) < 0.001.  
\end{table}
Table 3: Results of significance tests for interactions between car’s initial speed, road’s lane width, VRU’s type, VRU’s location on LPG and RMS for each driver’s group.  
In this study, two types of roads were analyzed: 3.5-m-lane-width road with a centerline and 3.0-m-lane-width road without a centerline. The higher the lane width, the larger the passing gap is allowed. This is consistent with the rural-road studies [4,16,20,25]. It is worth notice that type C and type D drivers overtook VRU without a significant difference in LPG for the two roads.  
Besides, the Repeated Measures ANOVA tests on RMS showed a statistically significant effect on all types of drivers: F(1,34) = 11.96, \(p\) = 0.001, \(\eta^{2}_{\text{G}}\) = 0.099 (type A drivers), F(1,137) = 45.49, \(p\) < 0.0001, \(\eta^{2}_{\text{G}}\) = 0.075 (type B drivers), F(1,131) = 10.69, \(p\) = 0.001, \(\eta^{2}_{\text{G}}\) = 0.016 (type C drivers), F(1,71) = 4.01, \(p\) < 0.05, \(\eta^{2}_{\text{G}}\) = 0.022 (type D drivers). TukeyHSD tests showed statistically significant difference between RMS on 3.0 m lane width and 3.5 m lane width, with estimate values were \(-\)0.104 (SE = 0.028), \(-\)0.081 (SE = 0.019), \(-\)0.028 (SE = 0.013), \(-\)0.013 (SE = 0.007), respectively.  
From the analysis, it is confirmed that lane width had a significant effect on vehicle speed. Type A, type B, type C drivers always selected higher speeds on wide roads. However, there were no statistically significant effects of lane width on the lateral passing gap of type C drivers and the speed of type D drivers. These results can be explained by the perception of those drivers. Type C drivers always keep a constant gap to VRU. While type D drivers' speeding behavior was not affected by travel space of road.