How drivers respond to visual vs. auditory information in advisory traffic information systems

Figures & data

Table 1. Participants in the study by modality, age, gender, and driving experience.

Modality	Mean age (SD)	Gender (M/F)	Avg no of years with license (SD)
Visual	34.3 (13.5)	15/5	13.4 (13.6)
Auditory	39.9 (9.6)	18/12	18.3 (10.7)

Figure 1. ATIS interface. To the left, three road users are at a distance (represented by the white lines) behind, to the back right and front right of the car. To the right, there is a pedestrian at a distance in front of the car, and another quite close in the right back blind spot. Some sort of vehicle is very close to the car's right side.

Table 2. Thresholds of warnings in terms of time to collision (seconds) or safety margin (meters).

Information level	TTC (s)	Safety margin (m)	Visual effects	Sound effects
Informative	6–9 s	$<$4.5 m	White	–
Advisory	3–6 s	$<$3.5 (3) m	Orange	Original sound sample
Critical	$<$3 s	$<$2.5 (2) m	Red	Increased pitch and frequency of looping

Figure 2. Driving simulator setup (Wang, Lyckvi, and Chen 2016a).

Figure 3. Traffic incidents scenarios.

Figure 4. The change of collision number percentage by applying ATIS of two modalities.

Figure 5. The change of measures value by applying ATIS of different modalities. Error bar indicates one standard deviation (${}^{\ast \ast }p<0.05{,}^{\ast }p<0.1$, to illustrate the significance value of measure change affected by ATIS).

Table 3. Driver reaction patterns of different modalities (results from Single T-test/Wilcoxon rank sum test, ${}^{\ast \ast }p<0.05{,}^{\ast }p<0.1$).

		Mean value of the change (S.D.)
Scenario	Measure	Visual	Auditory
Red Cab	TTC (s)	0.31 (1.30)	6.00 (1.00)${}^{\ast \ast }$
	$V_m$ (m/s)	0.53 (0.33)${}^{\ast \ast }$	−0.20 (0.24)
	SDLP (m)	−0.08 (0.05)	0.12 (0.04)${}^{\ast \ast }$
	$Br{k}_P$ (%)	−10.32 (4.05)${}^{\ast \ast }$	1.48 (3.11)
Intersection	TTC (s)	0.33 (1.22)	3.03 (1.02)${}^{\ast \ast }$
	$V_m$ (m/s)	1.08 (0.31)${}^{\ast \ast }$	−0.29 (0.25)${}^{\ast }$
	SDLP (m)	0.08 (0.05)${}^{\ast }$	−0.005 (0.40)
	$Br{k}_P$ (%)	−10.54 (3.93)${}^{\ast }$	0.53 (3.17)
Pedestrian	TTC (s)	0.14 (1.25)	0.19 (1.07)
	$V_m$ (m/s)	0.14 (0.29)	0.21 (0.24)
	SDLP (m)	0.01 (0.05)	0.06 (0.04)${}^{\ast }$
	$Br{k}_P$ (%)	3.96 (3.71)	0.18 (3.11)

Table 4. Modality effect on the driver reaction patterns as a function of scenario (results from Simple effect test), ${}^{\ast \ast }p<0.05{,}^{\ast }p<0.1$).

		Simple effect of scenario${}^{\mathrm{b}}$
Measure${}^{\mathrm{a}}$	Degree of freedom	Visual	Auditory
TTC (s)	2, 113	0.007	7.89${}^{\ast \ast }$
$V_m$ (m/s)	2, 125	2.43${}^{\ast }$	1.19
SDLP (m)	2, 126	2.67${}^{\ast }$	2.43${}^{\ast }$
$Br{k}_P$ (%)	2, 126	4.77${}^{\ast \ast }$	0.05

${}^{\mathrm{a}}$All measures here display significant interaction effect between scenario and modality.

${}^{\mathrm{b}}$Passed Levene test; multi-comparison adjustment method: Sidak.

Table 5. A summary of modality effects on the driver reaction patterns across all scenarios (+ indicates positive significance, − indicates negative significance, o indicates no significance).

	Visual				Auditory
	Long.		Lat.	Coll. red.${}^{\mathrm{a}}$	Long.		Lat.	Coll. red.${}^{\mathrm{a}}$
Scenario	Efficiency	Safety			Efficiency	Safety
Red Cab	+	o	o	+	o	+	−	−
Intersection	+	o	o	o	o	+	o	+
Pedestrian	o	o	o	+	o	o	−	+

Notes: Long. and Lat. represent longitudinal and lateral control performance, respectively.

${}^{\mathrm{a}}$The degree to which the collision number is reduced after introducing ATIS of a modality (tendency).

Wang, MinJuan, Sus Lundgren Lyckvi, and Fang Chen. 2016a. “Why and How Traffic Safety Cultures Matter when Designing Advisory Traffic Information Systems.” Proceedings of the 2016 CHI Conference on Human Factors in Computing Systems, 2808–2818. ACM. https://doi.org/10.1145/2858036.2858467.

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Data availability

The data that support the findings of this study are available from Volvo Cars. Restrictions apply to the availability of these data, which were used under licence for this study. Data are available from MinJuan Wang with the permission of Volvo Cars.