The best way would be to jump but that is very seldom possible. If you are going to do something very physical, such as poke them in the eye, kick them in the knees or groin, make sure you can really pull it off with enough force. You may anger him to extreme violence. Practice the moves they are a good exercise. Turn on the emergency blinkers but do not stay in the car .
Predators look for cars that are broken down.
Call 911 they will send someone to help you. If you do not have a phone, try to walk off the road so you are not noticed until you get somewhere to get help. Some roads do not have much cover. Years ago I had to walk down a road and hit the ditch whenever I saw headlights. Unfortunately, it was wet from the rain and filled with leaves.