Should I have done something?

Last night when driving home from work, it was like 2-3 am. I saw a girl probably 14-16 walking along the side of the road, slowly with a backpack and a hoodie. She was looking down at the ground so I didn’t get a great look at her face, but she looked a bit scared. I didn’t think it was any of my business so I didn’t nothing. Looking back I feel like I should have called the cops. But I didn’t know the circumstances, she could be running away from an abuser, or she could just be walking home from a friends house. I feel almost guilty, cause what if some predator found her