In State v. Schultz, 123 Ariz. 120, 597 P.2d 1023 (App. 1979), the issue was whether 28-622.01 required proof that the pursuing law enforcement vehicle was "appropriately marked showing it to be an official law enforcement vehicle," when there was evidence that the police officer had activated "blinking red lights and revolving dome lights on top of his police vehicle as well as the siren and flashing headlights." Schultz, 123 Ariz. at 121, 597 P.2d at 1024. The Court held that 28-622.01 does require proof that the vehicle was appropriately marked as an official law enforcement vehicle. Because the officer in Schultz had activated his siren as well as multiple sets of lights, we did not address the specific question whether use of the siren is a separate, essential element of the offense. It is clear from the plain language of 28-624(C) that drivers of authorized emergency vehicles- and, by extension, law enforcement officers under 28-622.01- must only use a siren or other audible warning "as reasonably necessary. "Division One reached the same conclusion in Simkins v. Pulley, 116 Ariz. 487, 491, 569 P.2d 1385, 1389 (App. 1977), ruling that "the language of the statute itself sets forth the parameters of the duty 'as may be reasonably necessary.'" In so holding, the Simkins court refused to give dispositive weight to dictum in an earlier case, Herderick v. State, 23 Ariz. App. 111, 114, 530 P.2d 1144, 1147 (1975), declining to apply literally the gratuitous language in Herderick that "when exceeding the speed limits a patrolman must give warning by siren of his approach to other drivers and pedestrians on the highway."