Use your sixth sense...I once had a guy break into my apartment when I was a young single woman living alone. Luckily, I awoke by the sound of (the finite noise of a slack/jacket rubbing against one another) to find the stranger coming towards my bed and asked him "WTH are you doing here?" with my barely spoken/paralyzed scared voice. Apparently, I must have scared him as much as he did me because he left and did me no harm.
Regardless, it was ONE of the most scariest event in my life--among many others.
Anyways, while running, I've had strange encounters of fools trying to scare me while in their car yelling out "Hey you"...prior to sunrise and/or during daylight. I don't take any chances...I immediately put up my guard/senses and avoid the situation or constantly think ways to protect myself.
My weapon is my sharp car key that I carry between my fingers and my voice to yell and my body to "fight". In other words, if you're going to attack me then you picked the wrong person to do so...