Table 1 Question items based on theory of planned behavior with a five-point Likert scale

Attitude^a

1. Fastening the seat belt in the car will prevent my injury.

2. It is pleasant for me to wear a seat belt in the car.

3. Using a helmet while cycling will prevent my injury.

4. It is pleasant for me to use a helmet while cycling.

5. Crossing the sidewalk, escalator, and underpasses allowed to go to school will prevent my injury.

6. It is pleasant for me to cross the pedestrian crossings, escalators and authorized underground passages.

Subjective Norms^a

1. People who are important to me recommend that I fasten my seat belt in the car.

2. People who are important to me support me to fasten my seat belt in the car.

3. People who are important to me recommend that I wear a helmet while cycling.

4. People who are important to me support me to wear a helmet when cycling.

5. People who are important to me recommend that I go through pedestrian crossings, escalators, and underpasses.

6. People who are important to me support me in crossing pedestrian crossings, escalators and authorized underground passages.

Perceived behavioral control^a

1. It is easy for me to use a seat belt in the car.

2. I can fasten my seat belt in the car in any situation.

3. It is easy for me to use a helmet while cycling.

4. I can use a helmet in any situation while cycling.

5. It is easy for me to cross pedestrian crossings, escalators and authorized underground passages.

6. I can cross pedestrian crossings, escalators and authorized underground passages in any situation.

Behavioral intention^a

1. I intend to do safety traffic behavior more.

2. I intend to fasten my seat belt in the car.

3. I intend to use a helmet when cycling.

Behavior^b

1. I fasten my seat belt in the car.

2. I wear a helmet when cycling.

3. I cross pedestrian crossings, escalators and authorized underground passages.