California Code of Regulations
Title 13 - Motor Vehicles
Division 2 - Department of the California Highway Patrol
Chapter 4 - Special Equipment
Article 8.5 - HI-LO Audible Warning Sound
Section 1029.2 - Hi-Lo Audible Warning Sound Requirements

Universal Citation: 13 CA Code of Regs 1029.2

Current through Register 2024 Notice Reg. No. 38, September 20, 2024

(a) Audible Warning Sound Functions. To be considered compliant with this article, the Hi-Lo Audible Warning Sound shall meet the following requirements:

(1) The activation switch shall be clearly marked as "Hi-Lo" on a control panel.

(2) The sound shall be a continuous, unbroken, repetitive, two-tone electronic sound from time of activation until deactivation.

(3) The sound shall not be a siren, air horn, buzzer, or shrill-type sound.

(4) The sound shall not be capable of functioning simultaneously, or in conjunction with a siren, if so equipped.

(b) Sound Level Output. To be considered compliant with this article, the Hi-Lo Audible Warning Sound shall meet the following requirements:

(1) The sound shall perform at a minimum decibel (dB) range of 100 dB to a maximum of 130 dB as measured at zero degrees, 10 feet in front of the speaker.

(c) Sound Duration. To be considered compliant with this article, the Hi-Lo Audible Warning Sound shall meet the following requirements:

(1) Sound duration type shall meet one of the following three Hertz (Hz) cycling frequency ratings:
(A) Between 659 Hz cycles per second for the Hi tone and 554 Hz cycles per second for the Lo tone ("European Hi-Lo") or;

(B) Between 932 Hz cycles per second for the Hi tone and 740 Hz cycles per second for the Lo tone ("USA Hi-Lo") or;

(C) Between 1244 Hz cycles per second for the Hi tone and 1046 Hz cycles per second for the Lo tone ("California Hi-Lo").

(2) The operational mode of the alternating Hi-Lo tones shall be active between a nominal minimum cycling rate of 35 cycles per minute to a maximum of 80 cycles per minute with no break or pause between tone switching.

(d) Only one of the three required sound duration types shall be used as a Hi-Lo Audible Warning Sound.

1. New section filed 6-24-2021; operative 6-24-2021 pursuant to Government Code section 11343.4(b)(3) (Register 2021, No. 26).

Note: Authority cited: Section 27002, Vehicle Code. Reference: Section 27002, Vehicle Code.

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