Effects of Safety Facilities on Driver Distance Perception in Expressway Tunnels
Table 2
Subjective effects of safety facilities on driver behavior.
Safety facility
Driver behavior
Very negative
Slightly negative
Neutral
Slightly positive
Very positive
Mean
Standard Deviation
1
2
3
4
5
Information boards
Increase attention
4.36
5.96
8.72
56.19
24.77
3.91
0.98
Decelerate
4.13
8.49
9.63
24.54
53.21
4.14
1.15
Keep space
10.32
7.11
11.47
44.04
27.06
3.70
1.23
Flashing lights
Increase attention
2.06
1.61
22.71
35.09
38.53
4.06
0.93
Decelerate
2.98
4.13
18.81
37.39
36.70
4.01
0.99
Keep space
6.42
13.07
25.00
22.48
33.03
3.63
1.24
Human-voice
Increase attention
0.00
7.57
5.28
46.33
40.83
4.20
0.85
Decelerate
0.00
5.28
4.36
36.70
53.67
4.39
0.80
Keep space
28.21
26.61
13.53
20.64
11.01
2.60
1.37
Siren
Increase attention
2.52
19.27
1.83
26.38
50.00
4.02
1.23
Decelerate
3.67
3.21
10.32
34.86
47.94
4.20
1.00
Keep space
15.60
22.71
11.01
34.17
16.51
3.13
1.35
Note: 42.2% of drivers had never heard cable broadcasts and based responses on expectation not experiences. Analyses excluding these 42.2% of participants showed a similar pattern to those reported in Table 2.
