St. Peters, MO Noise from Specific Sources: Car Alarm Limits (2026)
Key Facts
- Banned
- Sounding a horn, signal device or any device on a stationary vehicle
- Exception
- Genuine danger signal or braking/decelerating warning
- Also banned
- Unreasonably loud/harsh sound or unnecessary sounding duration
- Exempt
- Authorized emergency-vehicle sirens (Section 210.390(G)(4))
- Penalty
- Fine up to $500 per day (Section 210.390(I)(5))
- Citation
- St. Peters Municipal Code Section 210.390(C)(1)
Summary
Section 210.390(C)(1) of the St. Peters Municipal Code bans sounding a horn, signal device, or "any device" on a stationary automobile, motorcycle, bus or other vehicle, except as a genuine danger signal, and separately bans creating an unreasonably loud or harsh signal sound or sounding a device for an unnecessary and unreasonable period. It is the provision the City applies to a car alarm that will not stop.
1. The sounding of any horn or signal device or any device on any automobile, motorcycle, bus or other vehicle while not in motion, except as a danger signal if another vehicle is approaching apparently out of control, or if in motion, only as a danger signal after or as brakes are being applied and deceleration of the vehicle is intended; the creation by means of any such signal device of any unreasonably loud or harsh sound; and the sounding of such device for an unnecessary and unreasonable period of time.
Full Breakdown
Item 1 of the noises "expressly prohibited" list in Section 210.390(C), last amended by Ordinance No. 7236 on December 19, 2019, covers three distinct acts: sounding a horn, signal device, or any device on a vehicle that is not in motion, with a narrow exception for a genuine danger signal if another vehicle is approaching out of control or as brakes are applied while decelerating; creating an unreasonably loud or harsh sound through any such signal device; and sounding a device for an unnecessary and unreasonable period of time.
A repeatedly triggering car alarm on a parked vehicle falls within the first and third clauses because it is a signal device sounding while the vehicle is stationary for longer than necessary. Section 210.390(G)(4) separately exempts noise from any authorized emergency vehicle, so police, fire and ambulance sirens are not reached by this item. Enforcement runs through the same Code Enforcement Officer and notice-and-hearing procedure in Subsection I that governs the rest of Section 210.390, with the City Administrator or a duly authorized representative fielding complaints before any referral to the Police Department for a Municipal Court complaint. A conviction is capped at a $500 fine under Subsection I(5), and each day a violation continues is a separate offense.
Violations & Fines
A complaint about a horn, signal device or alarm sounding on a stationary vehicle is handled through the Section 210.390(I) process: written notice from the Code Enforcement Officer, a hearing at least seven days out if contested, and referral to the Police Department for a Municipal Court complaint if unresolved. Section 210.390(I)(5) caps the fine at $500 upon conviction, with each day of a continuing violation treated as a separate offense.
Frequently Asked Questions
Is a car alarm that keeps going off illegal in St. Peters?
Are police and fire sirens exempt from this rule?
Who investigates a complaint about a car alarm noise?
What is the maximum penalty for violating this horn/alarm rule?
Sources & Official References
Other rules in St. Peters
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