September 14, 2026 Abdullah Haris

Pennsylvania Emergency Vehicle Light Laws: Statute, Flash Rate Limits and Equipment Standards

Key Takeaways

Pennsylvania regulates emergency lighting in two layers. 75 Pa.C.S. §§ 4571 and 4572 assign color by vehicle class, and 67 Pa. Code Chapter 173 sets the binding equipment specification.
Pennsylvania requires a flash rate between 60 and 260 flashes per minute when observed from a fixed position, under 67 Pa. Code § 173.3.
Flashing and revolving lights in Pennsylvania must meet or exceed the Chromaticity Coordinates of the CIE 1931 Standard Colorimetric System as provided in SAE Standard J578d or a subsequent SAE standard.
White, clear, red, blue, amber and yellow are the only colors permitted for flashing or revolving lights in Pennsylvania under 67 Pa. Code § 173.3(a).
Combination red and blue lights in Pennsylvania may be used only on police, sheriff, coroner, medical examiner or fire police vehicles, under 75 Pa.C.S. § 4571(b).
Unauthorized use of emergency warning equipment in Pennsylvania is a summary offense punishable by a fine of not less than $500 and not more than $1,000 under 75 Pa.C.S. § 4571(e).

Pennsylvania splits its warning light rules across two layers, and most published guides only cover the first one. The statute, 75 Pa.C.S. §§ 4571 and 4572, sets out who may display what color. The regulation, 67 Pa. Code Chapter 173, sets out the technical specifications the equipment has to meet.

If you are buying equipment for a Pennsylvania fleet, Chapter 173 is where the purchasing decisions actually get made. It covers flash rate, color standards, mounting for 360-degree visibility and light bar assembly configuration.

The Details Within The Law: Sections 4571 & 4572

Section 4571(a) sets the baseline for emergency vehicles: every emergency vehicle shall be equipped with one or more revolving or flashing red lights and an audible warning system. Spotlights with adjustable sockets may be attached or mounted.

Section 4571(b) adds blue. Police, sheriff, coroner, medical examiner and fire police vehicles may, in addition to the red requirement, be equipped with one or more revolving or flashing blue lights. The statute is explicit that the combination of red and blue may be used only on police, sheriff, coroner, medical examiner, or fire police vehicles.

Fire police being included in the red and blue combination list is a Pennsylvania-specific feature that surprises people from other states. Note, however, that the vehicle has to qualify. PennDOT has taken the position that privately owned vehicles of fire police officers are not emergency vehicles and are regulated by section 4572, while fire police vehicles owned by a fire company are entitled to combination red and blue as well as traffic control emergency directional light assemblies.

Authorized Period of Use & The Penalty

Section 4571(e) limits use to during an emergency, in the interest of public safety, or by police officers, sheriffs and deputy sheriffs in enforcement of the law.

Unauthorized use is a summary offense punishable by a fine of not less than $500 and not more than $1,000. That is among the steeper penalties in the Northeast and worth putting in front of anyone who thinks of a warning light as a convenience item.

Section 4571(f) is the hook into the regulation: all equipment authorized or required by the section shall conform to department regulations. That is what makes Chapter 173 binding rather than advisory.

The Specification Layer: 67 Pa. Code Chapter 173

Chapter 173 sets the nature, display, color, standards and configuration for flashing, revolving, and oscillating lights on emergency and authorized vehicles. Section 173.3 carries the display requirements.

Specification	Requirement under Chapter 173
Permitted colors	White, clear, red, blue, amber or yellow are the only colors permitted for flashing or revolving lights, subject to the exception in 173.3(a.1).
Color standard	Lights must meet or exceed the Chromaticity Coordinates, CIE 1931 Standard Colorimetric System, per SAE Standard J578d or subsequent SAE standards. Flashing headlamp systems are excepted.
Flash rate	Between 60 and 260 flashes per minute when observed from a fixed position.
Blue light bars	Vehicles described in 75 Pa.C.S. § 4572(a) may be equipped with a light bar assembly using only blue lights.
Amber light bars	Authorized vehicles under § 4572(b) may use flashing or revolving yellow or amber lights, or one or more light bar assemblies containing only yellow or amber lights.
360 degree visibility	When more than one light is used to provide 360 degree visibility, the number of lights may not exceed those specified in §§ 4571 and 4572.
Unmarked police vehicles	Combination lights must be mounted to provide visibility to vehicles approaching from the front and rear, regardless of mounting method.
Traffic control directional assemblies	Authorized vehicles used in construction, repair or maintenance of a bridge or highway may be equipped with traffic control emergency directional light assemblies.

The flash rate window is the specification most often missed. Many aftermarket LED heads ship with patterns that run well outside 60 to 260 flashes per minute, and some programmable controllers include patterns that would not comply if used in Pennsylvania. Check the pattern, not just the color.

The SAE J578 chromaticity reference is the other one. It means "blue" in Pennsylvania is a defined coordinate range, not a marketing description. Reputable manufacturers publish SAE compliance for their lightheads. Unbranded imports frequently do not.

Amber & Authorized Vehicles Under 4572

Section 4572 governs visual signals on authorized vehicles, which is the category covering highway construction and maintenance vehicles, and section 4572.1 addresses flashing or revolving yellow and white lights. Section 4572.2 covers solid waste collection vehicles.

Pennsylvania's separate treatment of solid waste collection vehicles is unusual and worth noting for refuse fleet managers, who often assume they fall under generic amber rules.

Buying For a Pennsylvania Fleet

Because Chapter 173 is a specification regulation, brand matters more in Pennsylvania than in states that only legislate color. Manufacturers that publish SAE J578 compliance and controllable flash patterns make compliance documentable. We stock Whelen, Federal Signal, SoundOff Signal and Feniex for exactly this reason.

For police, sheriff and fire police vehicles running combination red and blue, full size lightbars paired with programmable switches and controllers let you keep flash rate inside the regulated window across every pattern.

Construction, maintenance and refuse fleets should start with amber lights, arrow and traffic advisor bars for the directional assemblies referenced in Chapter 173, and 360 degree beacons where full visibility is required.

Frequently asked questions

What is the legal flash rate for emergency lights in Pennsylvania?

67 Pa. Code § 173.3 requires a flash rate between 60 and 260 flashes per minute when observed from a fixed position.

Can Pennsylvania fire police use red and blue lights?

Fire police vehicles are among the classes listed in 75 Pa.C.S. § 4571(b) that may display combination red and blue lights. PennDOT has stated that privately owned vehicles of fire police officers are not emergency vehicles and fall under section 4572 instead.

What is the penalty for illegal emergency lights in Pennsylvania?

Under 75 Pa.C.S. § 4571(e), unauthorized use is a summary offense punishable by a fine of not less than $500 and not more than $1,000.

What colors are legal for flashing lights in Pennsylvania?

67 Pa. Code § 173.3 permits white, clear, red, blue, amber or yellow for flashing or revolving lights, subject to the exception in subsection (a.1), and requires the lights to meet SAE J578d chromaticity coordinates or a subsequent SAE standard.

Last updated and disclaimer

Last reviewed: August 2026. This page summarizes 75 Pa.C.S. §§ 4571-4573; 67 Pa. Code Ch. 173 and related provisions for general informational purposes. It is not legal advice. Statutes are amended and agency requirements change. Confirm current requirements with the official sources linked above, your department or agency, and the relevant state motor vehicle authority before purchasing or installing warning equipment.

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