Which of the following is NOT one of the five requirements of a traffic control device?

Answer: C — Increase speed

The correct answer, which is that increasing speed is not one of the five requirements of a traffic control device, highlights the primary purpose of these devices. Traffic control devices are designed to enhance safety and improve the flow of traffic while ensuring that drivers and pedestrians are aware of certain conditions and rules. To fulfill their intended role, a traffic control device must meet specific criteria: it should fulfill a need, command respect, and convey a clear and simple message. Focusing on increasing speed contradicts the fundamental objectives of these devices, which are primarily concerned with regulating, warning, and guiding road users. The emphasis on commands and clarity is critical for fostering compliance and understanding among motorists and pedestrians regarding road conditions, potential hazards, and proper navigational instructions. Therefore, a requirement to increase speed is not aligned with the essential functions of traffic control devices.