Just to add to the Interstate hooker mythos, I was once driving back to NY from Florida when I stopped at this place called "South of the Border" (its either on the border of NC and SC or NC and VA). I dont remember the particulars but its a place where there is no sales tax or something (this was 8 yrs ago, forgive me if my memory is faulty), so its a last stop to get cheap goods before crossing over into the next state. Its right off I-95.
Anyway, I saw this place, was a bit tired and stopped to grab a drink. While I was in the parking lot drinking my soda and reading the paper, I noticed this brunette wandering around. She walked by my car, smiled, I smiled back, etc. etc. She stopped to talk to me and let me know, basically, that she was available. Cost $50 for a BBBJ and F/S (again 8 yrs ago). To this day she ranks as one of the 10 best BJs I've ever had. Even though I blew my load during the BJ, she still slapped a rubber on me and let me fuck her in the front seat (not an easy feat in a mustang) with one leg out the window.
Later on, after I caught a couple hours of sleep, I spotted another woman who I thought was a hooker and asked her deal. She ended up not being a hooker (so she said) but gave me a blow job for giving her a 15-20 mile ride up the interstate.
I stopped at a few places after that, most notably in VA and NJ, but never saw anyone I would approach. But, just from that one trip, I learned you never know where you are going to find some play.