Table 1 Description of study instrument

1)Perceived susceptibility: It refers to subjective assessment of risk of developing a health problem

5 items/ 5 point Likert Scale

Strongly Disagree = 1, Disagree = 2, No idea = 3, Agree = 4, Strongly Agree = 5

(5–25)

0.79

If I drive with unauthorized speed, I’m likely to crash

2) Perceived severity: It refers to the subjective assessment of the severity of a health problem and its potential consequences.

5 items/5 point Likert Scale (strongly disagree- strongly agree)

SD = 1, D = 2, NI = 3, A = 4, SA = 5^a

(5–25)

0.84

If I have driving accident, I will suffer from long-term complications.

3) Perceived benefits: Health-related behaviors are also influenced by the perceived benefits of taking action.

6 items/5 point Likert Scale (strongly disagree- strongly agree)

SD = 1, D = 2, NI = 3, A = 4, SA = 5

(6–30)

0.81

Avoiding hazardous driving behaviors will prevent personal and financial losses.

4) Perceived barriers: It refers to barrier to taking health-related actions.

5 items/5 point Likert Scale (strongly disagree- strongly agree)

SD = 1, D = 2, NI = 3, A = 4, SA = 5

(5–25)

0.85

The temptation to transfer more passenger makes me stop driving safely.

5) Self-efficacy: It refers to an individual’s perception of his or her competence to successfully perform a behavior

4 items/5 point Likert Scale (strongly disagree- strongly agree)

SD = 1, D = 2, NI = 3, A = 4, SA = 5

(4–20)

0.76

The insistence of passengers does not make me to undertake risky driving behaviors.

6) Safe behavior: It refers to health-related behaviors and practices.

32 items / 4 point

never = 1, sometimes = 2, most of the time = 3, Always = 4)

(32–128)

–

- Use mobile phone while driving

- Exchanging money with passengers while driving