Assessing the Effects of Interchange Warning Systems on Driving Risk: A Driving Simulator Study

Table 6

The results of the independent samples t-test.

Characteristics type	Characteristics	IWS	Scenario 1	Scenario 2	Scenario 3	Scenario 4
Operation behavior	Mean speed (km/h)	Unapplied	58.02	75.31	86.36	41.40
		Applied	57.62	64.33	64.15	50.45
		Sig	0.902	0.002	0.000	0.005
	Speed SD (km/h)	Unapplied	0.64	0.81	0.35	1.60
		Applied	1.03	1.60	0.65	1.81
		Sig	0.017	0.000	0.042	0.202
	Acceleration SD (m/s^2)	Unapplied	6.38	6.66	3.58	14.23
		Applied	7.88	11.18	7.83	16.15
		Sig	0.186	0.018	0.001	0.235
	Mean brake pedal depth	Unapplied	3.51	5.51	2.41	11.32
		Applied	6.02	10.10	3.03	10.87
		Sig	0.039	0.009	0.357	0.708
	Maximum brake pedal depth	Unapplied	0.27	0.83	0.22	0.94
		Applied	0.37	1.08	0.2	1.55
		Sig	0.376	0.047	0.838	0.410
	Brake pedal depth SD	Unapplied	0.82	1.64	0.40	2.60
		Applied	1.19	3.09	0.65	2.76
		Sig	0.232	0.015	0.358	0.711
Psychophysiological characteristics	Heart rate SD	Unapplied	3.73	4.84	4.3	5.44
		Applied	4.69	4.22	3.99	5.07
		Sig	0.335	0.562	0.779	0.712
	Electrodermal activity (μS)	Unapplied	7.16	7.67	6.71	7.25
		Applied	7.08	7.21	7.49	8.08
		Sig	0.691	0.67	0.309	0.574
Eye movement characteristics	Mean saccade amplitude (°)	Unapplied	2.56	2.19	1.6	2.84
		Applied	2.58	2.56	2.14	2.20
		Sig	0.976	0.231	0.029	0.265
	Mean saccade velocity (°/s)	Unapplied	64.67	72.16	53.61	72.84
		Applied	73.50	74.90	51.74	70.70
		Sig	0.045	0.623	0.918	0.637

Significant difference at 0.05 level. Significant difference at 0.01 level.