What type of traffic signal allows emergency vehicles to operate without stopping?

The correct answer is a red signal. Emergency vehicles are typically granted priority over standard traffic regulations when responding to emergencies. A red signal indicates that regular traffic must stop; however, emergency vehicles are often permitted to proceed through a red signal when using their lights and sirens. This allows them to navigate intersections and reach their destinations more efficiently during critical situations.

In contrast, a yield signal requires drivers to yield the right-of-way to other vehicles and pedestrians, which could impede the progress of an emergency vehicle. A stop signal explicitly directs all vehicles to stop and would not provide the necessary clearance for emergency responders. A green signal allows normal traffic to proceed, but it does not specifically cater to the needs of emergency vehicles attempting to navigate through traffic.