Related Clues:

• Difficult road layouts
• States borders?
• Challenging curves
• Pluralizing letters
• Tee preceders
• Sinuous letters
• Curvy road segments
• Winding roads
• Class closing?
• Double-curve shapes
• Outsides of sandwiches?
• Mountain road curves
• Test track features
• ''Sissy,'' mostly
• Pothooks