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Figure 1.
Device used during the experiment.
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Figure 2.
Correlation heatmap.
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Figure 3.
Probability distribution histogram plot of driver fatigue states.
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Figure 4.
Variation in FDD over time under different working conditions for each participant.
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Figure 5.
Distribution plot of FDD in extra-long tunnel.
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Figure 6.
Mechanism of the fatigue arousal zone.
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Figure 7.
Variation in average FDD over time under different working conditions.
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Figure 8.
Diagram of the sign recognition process.
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Condition Tunnel name Distance to upstream tunnel exit (m) Length (m) Road type 1 Wadianzi tunnel-Tiefengshan expressway − 13,800 Open road 2 Dashu tunnel group Dashu tunnel − 5,825 Tunnel group Kuzhuba tunnel 320 Wangjia tunnel 220 Longquan tunnel 70 3 Longjing tunnel group Longjing tunnel − 13,448 Tunnel group Daping tunnel 80 Guangchengshan tunnel 270 Yousha tunnel 322 Xiaoling tunnel 112 Dongqiao tunnel 380 Yanghegou tunnel 116 4 Wadianzi tunnel − 3,356 Extra-long tunnel 5 Tiefengshan tunnel − 11,362 Extra-long tunnel 6 Nanshan tunnel − 4,828 Extra-long tunnel Table 1.
Information of experimental tunnels.
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Test indicator Pairing method Normal distribution Test method T/Z Significance level Blink frequency Awake & Semi-fatigue state Disobey Wilcoxon test −5.062 0.000* Awake & Fatigue state Disobey Wilcoxon test −0.939 0.000* Semi-fatigue & Fatigue state Disobey Wilcoxon test −9.302 0.000* Average blink duration Awake & Semi-fatigue state Disobey Wilcoxon test −5.534 0.000* Awake & Fatigue state Disobey Wilcoxon test −4.511 0.000* Semi-fatigue & Fatigue state Disobey Wilcoxon test −2.233 0.026 Perclos P80 Awake & Semi-fatigue state Disobey Wilcoxon test −7.646 0.000* Awake & Fatigue state Disobey Wilcoxon test −25.607 0.000* Semi-fatigue & Fatigue state Obey T-test −11.782 0.000* Average fixation duration Awake & Semi-fatigue state Disobey Wilcoxon test −1.689 0.091 Awake & Fatigue state Disobey Wilcoxon test −1.689 0.253 Semi-fatigue & Fatigue state Disobey Wilcoxon test −2.183 0.029 Variable coefficient of pupil diameter Awake & Semi-fatigue state Obey T-test 0.675 0.000* Awake & Fatigue state Obey T-test −2.926 0.000* Semi-fatigue & Fatigue state Obey T-test −3.579 0.001* Speed Awake & Semi-fatigue state Disobey Wilcoxon test 31.174 0.043 Awake & Fatigue state Disobey Wilcoxon test −38.082 0.000* Semi-fatigue & Fatigue state Disobey Wilcoxon test −26.023 0.000* Acceleration Awake & Semi-fatigue state Obey T-test −2.023 0.000* Awake & Fatigue state Disobey Wilcoxon test −15.611 0.000* Semi-fatigue & Fatigue state Disobey Wilcoxon test −19.166 0.000* * indicates a significance level less than 0.05, indicating a significant difference between the two groups. Table 2.
Significance test of difference.
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Test indicator Significance test
of differenceCorrelation analysis Blink frequency Significant Moderately relevant Average blink duration Insignificant Irrelevant Perclos P80 Significant More relevant Average fixation duration Insignificant Irrelevant Variable coefficient of pupil diameter Significant More relevant Speed Insignificant Irrelevant Acceleration Significant More relevant Table 3.
Summary of the analysis of each test indicator.
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Variable type Variable name Variable assignment Unit Encoding Explanatory variable Perclos P80 x1 % Covariate Variable coefficient of pupil diameter x2 − Covariate Acceleration x3 m/s2 Covariate Influencing variable Cumulative driving time x4 s Covariate Working condition driving time x5 s Covariate Tunnel length x6 m Covariate Tunnel illuminance x7 Lux Covariate Horizontal curve CCR x8 °/m Covariate Is it a parking harbor x9 − 0 = No,
1 = YesIs it an open road x10 − 0 = No,
1 = YesThe covariate is a continuous variable. Table 4.
Variable selection and encoding.
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Variable Estimated value Standard error Wald Degree of freedom Significance Exp (β) Threshold [Fatigue level = 1] 1.270 0.642 3.917 1 0.048 − [Fatigue level = 2] 6.568 0.859 58.502 1 0.000 − Location Perclos P80 12.136 5.183 10.930 1 0.000 186 465.218 Variable coefficient of pupil diameter 0.373 0.048 60.723 1 0.001 1.075 Cumulative driving time 2.634 3.855 15.135 1 0.000 13.929 Working condition driving time 0.264 1.913 13.260 1 0.000 1.302 Tunnel length 0.395 0.036 28.014 1 0.000 1.484 [Is it an open road = 0] −0.293 0.566 0.116 1 0.000 0.746 [Is it an open road = 1] 0a − − 0 − − a: This parameter is set to zero because it is redundant. Table 5.
Ordered multi-class Logistic regression results.
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State Awake Semi-Fatigue Fatigue Perclos P80 (%) (0, 8) [8, 17.5] (17.5, ∞) Table 6.
Driving fatigue discrimination standard.
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Tunnel section Middle section illuminance (lux) Selected material Reflectance coefficient Luminance
(cd/m2)The fatigue arousal
zone luminance (cd/m2)Road surface 64.89 Asphalt road surface 0.14 9.08 27.24 Cement road surface 0.31 20.11 60.33 Ceiling 36.26 Gray-black paint 0.41 14.87 44.61 Gray paint 0.63 22.84 68.52 Light gray paint 0.69 25.02 75.06 White paint 0.73 26.47 79.41 Side wall 45.50 Gray paint 0.63 28.67 86.01 Table 7.
Maximum brightness values for various parts of the fatigue arousal zone.
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Tunnel name Tunnel length (m) Amount Interval (m) Length (m) Form Introduction signs Zhongnanshan highway Tunnel 18,200 3 4,500 150 Blue sky and white clouds, sunset glow, 3D decorations Doesn't exist New erlangshan tunnel 13,459 3 4,000 120 The five-starred red flag, starry sky, maple leaf Exist Dapingni tunnel 12,300 2 4,000 100 Blue sky and white clouds − Chengkai tunnel 11,456 4 2,500 100 Four seasons landscape, 3D decorations Exist Yunshan tunnel 11,403 1 5,500 200 Color light strip Doesn't exist Baojiashan tunnel 11,200 1 − 200 Color light strip, 3D decorations Doesn't exist Baotashan tunnel 10,200 2 3,500 200 Color light strip Exist Six pangshan special tunnel 9,981 1 5,000 200 Blue sky and white clouds, underwater world Doesn't exist Yanglin tunnel 9,460 1 4,700 150 Landscape painting scroll, 3D decorations Exist Baodingshan tunnel no.2 8,775 2 3,000 120 Blue sky and white clouds, rockery stone scenery − Wunvfeng tunnel 7,930 1 4,000 120 Blue sky and white clouds, color light strip Doesn't exist Malanshan tunnel 7,904 2 − 200 Underwater world, mountain and river scenery Doesn't exist Qiganshan Tunnel 7,630 1 3,600 300 Mountain and river scenery − Xuefeng mountain tunnel 7,040 14 3,500 − Blue sky and white clouds Doesn't exist Huayan Tunnel 5,100 4 1000 100 Blue sky and white clouds Doesn't exist Dushu lake tunnel 3,460 1 1,500 100 Color light strip Doesn't exist Table 8.
Design parameters statistics of the fatigue arousal zone of some extra-long tunnels in China.
Figures
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Tables
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