Table 2.

Correlation coefficients between item responses and factor scores.

No	Question	Response options	Work Pressure	Safety & Security Concerns
Q2	Your gender?	1 = Male, 2 = Female	0.05	−0.09
Q4	Where do you primarily drive?	1 = National, 2 = Benelux + Ruhr area, 3 = International	-0.21	0.51
Q5	How old are you?	1 = 18–25, 5 = 60–75	-0.03	0.00
Q13	Do you think the image of the driver needs to be improved?	1 = No, 3 = Yes	0.09	0.01
Q16	What is your general impression of the image of the professional driver?	1 = Very negative, 5 = Very positive	−0.19	−0.24
Q46	Would you recommend the profession to family or acquaintances?	1 = No, 2 = Yes	-0.22	-0.17
Q56	What grade would you generally give to the professional driver’s profession?	1 = Very bad, 10 = Very good	-0.37	-0.24
Q64	How do you see the future as a Dutch professional driver?	1 = Very negative, 10 = Very positive	−0.22	-0.34

Correlation coefficients with binary variables (Q2, Q46) are also known as point-biserial correlation coefficients. Given the substantial sample size (n = 3,708), minor correlations statistically deviate from zero, with p < 0.01 when |r| is greater than or equal to 0.05.