Which of the following is a requirement for a vehicle to be identified as an authorized emergency vehicle?

To be identified as an authorized emergency vehicle, equipping the vehicle with red lights is critical. Red lights are universally recognized as an indicator of priority response, primarily used by police, fire, and medical emergency services. The presence of red lights is essential as these vehicles often need to be granted right of way in traffic situations, and other road users recognize these signals as a sign of urgency.

While flashing yellow lights can indicate caution and are used in certain scenarios, they are not sufficient alone to classify a vehicle as an authorized emergency vehicle. The requirement for emergency training may apply to the operator of the vehicle, but it does not define the vehicle itself. Similarly, registration as a commercial vehicle does not pertain to the designation of an authorized emergency vehicle. Therefore, the correct identification hinges upon the presence of red lights to signal its status as an emergency vehicle effectively.