What do question marks in road signs mean? It's a blue sign with a white question mark?

Related questions

• Which of the following sentences requires a question mark?: How do you want me to make the...
• Which of the following sentences requires a question mark?: The doorbell just rang Do you think...
• Which of the following sentences requires a question mark?: The folder is somewhere on the...
• Which of the following sentences requires a question mark?: What is their insignia Who are they
• What is a question mark?
• What is the origin of the question mark?
• What is an interrogative sentence?
• Where did the question mark come from?
• Do you have to put a question mark after a rhetorical question?
• Question #94c55