Is a non-priority vehicle operating in an emergency service permitted to use acoustic signals?
A)Yes, but only within built-up areas.
B)No, they may only use optical signals.
C)Yes, to warn other road users of their presence.Correct
If, as a result of particularly serious circumstances, the driver of a non-priority vehicle is forced, without being able to resort to any other means, to carry out a service normally reserved for priority vehicles, they shall endeavour to make other road users aware of the special situation in which they are travelling, using the acoustic warning device intermittently and activating the hazard lights, if available, or waving a handkerchief or using a similar method. In any case, traffic regulations must be observed, especially at intersections.