Symbolism, Imagery, Allegory
Quentin keeps mentioning this dang ditch—what's going on there, exactly? Nancy walks down into the ditch and up the other side whenever she takes the laundry (balanced perfectly on her head along with her hat) from his family's house to the black area of Jefferson to wash it. More importantly, it's where she keeps thinking Jesus is hiding, waiting to murder her.
"I can feel him, Nancy said. "I can feel him laying yonder in the ditch." (2.17)
Oh, we get it. It's the #1 Spookiest Ditch In America because it's where jealous husbands with razors hidden under their shirts hang out, right?
Eh, sorta. Yes, Nancy thinks that Jesus is hanging out in the ditch like the troll under the bridge in the Billy Goats Gruff, ready to jump out and say "boo." But most important, the ditch symbolizes the crossroads in Jefferson. It is the dividing line between the white neighborhood and the black neighborhood. It's no-man's land.
Nancy has personal experience living between the black area of town (her house, her husband) and the white area of town (her employers—both the family she cooks for and the white customers she sleeps with). This has led to, literally, all the trouble in her life. Dividing herself between these separate (and super-duper unequal) worlds has messed her up. No wonder she regards the ditch, dividing as it does the white neighborhoods from the black, as creeptastic.
It's the #1 Spookiest Ditch In America because it represents something way spookier than one jealous husband with a razor. It represents segregation, racism, and inequality in the South. And boy oh boy, there is nothing more frightening than that.