(a) An authorized emergency vehicle may be equipped with a siren, exhaust whistle, or bell:
(1) of a type approved by the department; and
(2) that emits a sound audible under normal conditions at a distance of at least 500 feet.
(b) The operator of an authorized emergency vehicle shall use the siren, whistle, or bell when necessary to warn other vehicle operators or pedestrians of the approach of the emergency vehicle.
(c) Except as provided by this section, an authorized emergency vehicle shall be equipped with signal lamps that:
(1) are mounted as high and as widely spaced laterally as practicable;
(2) display four alternately flashing red lights, two located on the front at the same level and two located on the rear at the same level; and
(3) emit a light visible at a distance of 500 feet in normal sunlight.
(c-1) An authorized emergency vehicle may be equipped with signal lamps that display alternating or flashing white lights that comply with the requirements of Subsections (c)(1) and (3).
(d) A private vehicle operated by a volunteer firefighter responding to a fire alarm or a medical emergency may, but is not required to, be equipped with signal lamps that comply with the requirements of Subsection (c).
(e) A private vehicle operated by a volunteer firefighter responding to a fire alarm or a medical emergency may be equipped with a signal lamp that is temporarily attached to the vehicle roof and flashes a red light visible at a distance of at least 500 feet in normal sunlight.
(f) A police vehicle may, but is not required to, be equipped with signal lamps that comply with Subsection (c).