How are the underlined phrases are grammatical by themselves?

[Bhikkhu1991a]

Hello,

Could you please explain how the underlined phrases are grammatical by themselves in the transcript? For instance, are they considered complete sentences and are used informally?

Here is the transcript:

… and on the highway. Here are some tips to help you stay safe while on the road. First, the Do's. If you're traveling with more than one driver, try to switch drivers occasionally so that you don't spend too much time behind the wheel. Remember to stop frequently and take a break. Make sure you know the signs of drowsiness: missing road signs, difficulty focusing, and yawning. Now the Don'ts. Don't count on distractions such as the radio or an open window to keep you awake. And even …

Giving driving advice on safe driving to summer vacationers
TOEIC listening part IV, set 19, exercise 5

http://www.english-test.net/toeic/listening/giving_driving_advice_on_safe_driving_to_summer_vacationers

Thank you.

Best wishes,
Bhikkhu1991a.

[Mordant]

They are not full sentences, and that is informal.

[Banglar Mati]

From grammatical point of view they are not sentences. But they carry the meaning or sense clearly inspite of being parts of sentences.

[Torsten]

Hi Banglar, you probably mean 'from a grammatical point of view'?

TOEIC listening, question-response: How should we pay for the shipment?