Pull up alongside and get her attention

That ass alone is worth the effort to see what's what. Your valet would disapprove and lecture you at length about personal safety and not picking up strays, but whatever, you only live once right?

You slow down to a crawl and pull up alongside the girl, but she doesn't even look at you and keeps moving ahead. You frown a little bit and tap on the horn, and to your amusement she actually jumps in fright, her head turning as if only now realizing that you've been beside her. She heads toward you and you can see that aside from a nice ass she also has the wide hips and thin waist that complements her firm perky C-cup breasts making her body have a near perfect proportion. What was this beautiful girl doing in your mountain late at night?

"Hi! Good evening," she greets, with a high and almost innocent voice in your opinion, "I'm sorry, I was lost in my world."

She pulls back a strand of hair from her face, and you can see that she has a cute face, and even with the dim lighting of street lights you can tell how flushed her face was from all the walking, and you worry a little bit about how young she actually is.

"Good evening," you reply with your best reassuring smile, "It's far too dangerous for a little girl in the woods isn't it?"

"I'm not a little girl," she crosses her arms, pushing her breasts higher and unknowingly giving you an even better look at her cleavage, "I turned 18 yesterday."

"Happy birthday, then." You say, raising an eyebrow as you give the girl another good look. Her body language seems... childish, her defensiveness also belies her youth. You even notice her make a wide innocent smile after you greeted her. "So why is a young woman like yourself walking on this mountain road?"

She winces a little bit, uncrosses her arms, and meekly inserts her thumbs inside her shorts' waistband pulling her shorts a little higher.

"To be honest sir," she answers, "I'm on an adventure."

"An adventure."

"Yes sir."

"Do you even know where you are?" I ask her, "You're miles away from anywhere."

"Well, I figured this road leads to somewhere, right?" She answers, pointing further up the road.

"Yes," I tell her, "this road leads to my house. That's the only thing you'll see at the top of the mountain, and you'll have to turn around since the road just ends where I live."

A pensive look falls on her face as she mouths an Oh, and she looks back from where she came. She's been breathing heavily all this time, as an uphill trek even on paved roads must not have been easy for her. She looks back at me, and back at the road, and continues this for a few cycles. I can only imagine that she's convincing herself and gathering the conviction to ask me for a lift.