Possible Clues:

• Approval of how hikers present requests
• About the potential bus strike, a good sign
• Digital sign of approval as in Roman Colosseum
• Elevated digits as sign of approval
• Old Roman sign for mercy, with elevated digits
• Manual sign of approval
• Looking for a lift, okay?
• Bus damaged in knock gets green light, perhaps
• Such approval means General Tom's elated
• Sign of success