What type of sign would indicate a route for emergency vehicles?

The correct choice identifies that service signs are specifically designed to provide assistance to drivers, including information about routes and services. Emergency vehicle route signs are classified as service signs because they guide emergency vehicles to their destinations safely and efficiently, ensuring they can navigate through traffic swiftly in case of an emergency.

Service signs are typically utilized for providing information related to public services, points of interest, and critical road information that aids drivers in various situations. This type of sign plays a crucial role in emergency response by directing emergency vehicles, thus helping to minimize delays during critical situations.

In contrast, warning signs are primarily intended to alert drivers to potential hazards or changes in road conditions. Regulatory signs communicate laws that must be followed for safe driving. Informative signs generally share general information that isn't directly related to traffic regulations or emergency routing, making them less relevant for directing emergency vehicles.