Which option correctly describes the flags used at night for traffic control?

• A. Red flags with reflective tape used at night on a 30-inch staff.
• B. Blue flags used only during the day.
• C. Retroreflective Red flags, 24 x 24 inches on a minimum 36-inch staff.
• D. White flags with red reflective tape on a 36-inch staff.

Answer: (C)

Night visibility is the key issue in flagging. Flags used at night must be highly visible to approaching drivers, which is achieved by retroreflective material that reflects headlights back toward the driver. The standard flag is red, 24 by 24 inches, on a minimum 36-inch staff. This size and color provide a clear, recognizable signal without being unwieldy, and the longer staff elevates the flag into the driver's line of sight above the bumper and debris. The other options fall short: blue flags are not used at night for traffic control; a 30-inch staff is shorter than the recommended minimum, which can reduce visibility; white flags with red reflective tape are not the standard flag design for night flagging, and the material needs to be retroreflective to be seen in headlights.