Situational awareness goes a long way toward keeping you safe. Time equals opportunity, and when you can identify potential threats in advance, you can make choices and take action for your own safety.
For example, when you see an oncoming vehicle veer into your lane, you can honk your horn, slow down, or move over to reduce the odds (and potential damage) of a crash. Similarly, when you see, hear, or feel a possible threat, you may be able to leave, draw attention to yourself or the threat, ask others for assistance, call Security or 911, arm yourself with an improvised weapon, take cover, or otherwise prepare to defend yourself.
Being aware of your surroundings and noticing changes as they occur gives you options that can decrease the chance of assault and increase your chance of survival should one occur.
Observe your surroundings, listen to your intuition, and stay safe!