A subordinate clause is the one which cannot exist outside of the main, full, complete clause, it cannot exist on its own.
So, the subordinate clause in this sentence is 'that ran between two commercial buildings near the downtown area'.
Answer:
The paragraph starts off with kind of a philosophical hook "What we learn about our friends on a road trip may be very different from what we learn about them in their homes or at school", which is interesting because it is an idea that is bigger than the story. It gives relevant details such as the title of the story, author, main character, and setting, but doesn't give too much away.
Construction or Architect