When operating an ambulance during an emergency, you could use the red flashing overhead lights and not the siren when:

• A. There is little to no traffic in the streets
• B. You do not want to frighten other motorists and possibly cause an accident
• C. You do not want to frighten other motorists and possibly cause an accident
• D. Never. You are required by law to always use the siren during an emergency

Answer: (D)

The important idea is that audible warning accompanies visual warning when an emergency vehicle is responding. Red flashing lights alert others visually, but many drivers and pedestrians won’t react quickly enough if there’s no audible signal. The siren provides an immediate, unmistakable cue that an ambulance needs right of way, helping to move traffic and protect everyone on scene. Because of that, the standard practice is to use the siren whenever you’re operating in emergency mode, rather than relying on lights alone. So the best answer is that you are required by emergency vehicle operating rules to always use the siren during an emergency.