Safety Evaluation of Fog Warning Systems in a Connected Vehicle Environment Based on Sample Entropy

Table 3

Statistical analysis of index under light fog condition.

Zone	Group	Speed (km/h)			Acceleration (m/s^2)
		Mean (SD)		Difference between groups	Mean (SD)		Difference between groups
Whole zone	Group ①	106.032 (7.958)	≤0.001	①-②	0.207 (0.185)	≤0.001	①-②
	Group ②	92.625 (6.375)		①-③	0.218 (0.124)		①-③
	Group ③	93.585 (6.718)			0.238 (0.224)
Clear zone	Group ①	111.363 (2.823)	≤0.001	①-②	0.130 (0.090)	0.011	①-②
	Group ②	87.692 (6.696)		①-③	0.309 (0.121)		②-③
	Group ③	91.063 (8.424)		②-③	0.290 (0.101)
Transition zone	Group ①	115.647 (6.542)	≤0.001	①-②	0.289 (0.170)	0.063	—
	Group ②	98.225 (7.229)		①-③	0.201 (0.179)
	Group ③	102.302 (5.646)		②-③	0.220 (0.159)
Fog zone	Group ①	99.520 (6.001)	≤0.001	①-②	0.201 (0.141)	≤0.001	①-②
	Group ②	95.339 (3.459)		①-③	0.143 (0.106)		①-③
	Group ③	93.634 (3.454)		②-③	0.205 (0.139)		②-③

Significant at the 95% confidence level.