The speed limitations set forth in this chapter do not apply to authorized emergency vehicles or the rider of a police bicycle when responding to an emergency call or when in the pursuit of an actual or suspected perpetrator of a felony or in response to an incident dangerous to the public and the drivers thereof use an audible signaling device or a visual signaling device. This provision does not relieve the driver of an authorized emergency vehicle or the rider of a police bicycle from the duty to drive or ride with due regard for the safety of others.
(Iowa Code § 321.231) (1999 Code, § 63.06)