What is the primary purpose of sirens on emergency vehicles?

The primary purpose of sirens on emergency vehicles is to alert civilian traffic of the emergency vehicle's approach. This function is crucial for ensuring that other road users are aware of the responding emergency vehicle, allowing them to take appropriate action, such as pulling over or yielding the right of way. Sirens provide an audible warning that can be heard over the sounds of city noise, helping to prevent collisions and ensure a swift and safe passage for emergency responders as they reach their destination. This capability is essential for maintaining public safety and facilitating effective emergency response.

The other choices do not align with the main intent of sirens. Signaling the end of a work shift does not relate to emergency response. Indicating the vehicle's position to other emergency responders typically relies on visual signals, such as lights or positioning, rather than sirens. Playing a warning sound for wildlife is not a standard function of emergency vehicle sirens, which are specifically designed for human traffic interactions.