## 4 Results and Descriptive Analysis
### Driving Workload  
#### 4.2.1 Driving Workload Distribution in the Work Zone  
The heart rate of the participants in different areas of the work zone was 64-108 bpm, with an average of 87.58-89.67 bpm. The U-test results indicated that there were no significant differences in the heart rate of the participants in different areas at a 95% confidence level, which was proved to be normal. Road alignment, traffic operation state, overtaking, lane changing and other factors will affect drivers' driving workload. In order to analyze the relationship between the work zone layout and driving workload, the participants' physiological data under non-work-zone road conditions were excluded, and the frequency distribution of the participants' \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Area** & **C** & **D** & **E*** & **F** & **G** & **H*** \\ \hline \multirow{2}{*}{C} & \multirow{2}{*}{-} & 20.55 \# (\(v\)) & 7.19 \# (\(v\)) & 1.74 (\(v\)) & \(-\)2.46 \# (\(v\)) & - \\  & & 20.91 \# (\(v_{85}\)) & 9.92 \# (\(v_{85}\)) & 0.62 (\(v_{85}\)) & \(-\)5.36 \# (\(v_{85}\)) & - \\ \hline \multirow{2}{*}{D} & \(-\)20.55 \# (\(v\)) & \multirow{2}{*}{-} & \(-\)13.36 \# (\(v\)) & \(-\)18.81 \# (\(v\)) & \(-\)23.01 \# (\(v\)) & \(-\)13.86 \# (\(v\)) \\  & \(-\)20.91 \# (\(v_{85}\)) & & \(-\)10.99 \# (\(v_{85}\)) & \(-\)20.65 \# (\(v_{85}\)) & \(-\)26.27 \# (\(v_{85}\)) & \(-\)11.81 \# (\(v_{85}\)) \\ \hline \multirow{2}{*}{E*} & \(-\)7.19 \# (\(v\)) & 13.36 \# (\(v\)) & \multirow{2}{*}{-} & \(-\)5.45 \# (\(v\)) & \(-\)9.65 \# (\(v\)) & \(-\)0.50 (\(v\)) \\  & \(-\)9.92 \# (\(v_{85}\)) & 10.99 \# (\(v_{85}\)) & & \(-\)9.66 \# (\(v_{85}\)) & \(-\)15.28 \# (\(v_{85}\)) & \(-\)0.82 (\(v_{85}\)) \\ \hline \multirow{2}{*}{F} & \(-\)1.74 (\(v\)) & 18.81 \# (\(v\)) & 5.45 \# (\(v\)) & \multirow{2}{*}{-} & \(-\)4.20 \# (\(v\)) & 4.95 \# (\(v\)) \\  & \(-\)0.62 (\(v_{85}\)) & 20.65 \# (\(v_{85}\)) & 9.66 \# (\(v_{85}\)) & & \(-\)5.62 \# (\(v_{85}\)) & 8.84 \# (\(v_{85}\)) \\ \hline \multirow{2}{*}{G} & 2.46 \# (\(v\)) & 23.01 \# (\(v\)) & 9.65 \# (\(v\)) & 4.20 \# (\(v\)) & & 9.15 \# (\(v\)) \\  & 5.36 \# (\(v_{85}\)) & 26.27 \# (\(v_{85}\)) & 15.28 \# (\(v_{85}\)) & 5.62 \# (\(v_{85}\)) & & 14.46 \# (\(v_{85}\)) \\ \hline \multirow{2}{*}{H***} & \multirow{2}{*}{-} & 13.86 \# (\(v\)) & 0.50 (\(v\)) & \(-\)4.95 \# (\(v\)) & \(-\)9.15 \# (\(v\)) & \\  & & 11.81 \# (\(v_{85}\)) & 0.82 (\(v_{85}\)) & \(-\)8.84 \# (\(v_{85}\)) & \(-\)14.46 \# (\(v_{85}\)) \\ \hline \hline \end{tabular}  
* means that the running speed is consistent with the speed limit at the 95% confidence level based on a U-test.
* means that there is a significant difference at the 95% confidence level based on a U-test.  
\end{table} 
Table 5: Speed differences and speed consistency for different median opening lengths in different areas. The U-test results indicated that there were significant differences in driving workload in different areas (A, B, C, H, I) at a 95% confidence level. A significant difference was found in the driving workload of different vehicles in areas B, C and I, where the road traffic conditions changed significantly; the mean value and volatility were both higher for trucks than for cars. In the standard freeway section (A), the road alignment and traffic conditions were good, so the driving task was relatively simple, and the driving workload was not significantly different between different vehicles, being low overall; at the beginning of the experiment, participants maintained a better mental state for driving, but after driving for a