TN Code § 55-9-414 (2021)
2021 Tennessee Code|Title 55 - Motor and Other Vehicles|Chapter 9 - Equipment — Lighting Regulations|Part 4 - Lighting Regulations|§ 55-9-414. Blue Flashing Emergency Lights on Motor Vehicles Unlawful — Exception — Penalty

   Except as provided in subsections (b)-(f), it is an offense for anyone to install, maintain or exhibit blue flashing emergency lights or blue flashing emergency lights in combination with red flashing emergency lights, except full-time, salaried, uniformed law enforcement officers of the state, county, or city and municipal governments of the state, and commissioned members of the Tennessee bureau of investigation when their official duties so require as defined by §§ 38-8-106 and 38-8-107.   A violation of subdivision (a)(1) is a Class C misdemeanor.      The prohibition in subsection (a) does not apply to the motor vehicles of constables who are wearing law enforcement uniforms designated by the governing body of the county in which they serve in those counties in which the constables retain law enforcement powers and duties under §§ 8-10-108, 39-17-505, 40-6-210, 55-8-152, 57-5-202 and 57-9-101.   Subdivision (b)(1) shall apply only to those counties having a population of:  not less than  nor more than   11,100 11,200   11,500 11,600   13,975 14,500   43,000 44,000   65,750 66,000   70,000 74,000   according to the 1970 federal census or any subsequent federal census.      The prohibition of subsection (a) does not apply to official motor vehicles of the sheriff's department being operated by reserve or auxiliary deputy sheriffs duly authorized by the sheriff and appointed pursuant to title 8, chapter 20. These  reserve or auxiliary officers operating departmental vehicles shall be in uniform and carry appropriate identification issued by the sheriff.   The prohibition of subsection (a) does not apply to motor vehicles of specially commissioned police officers employed pursuant to § 49-7-118(f) when operating either within five (5) miles of any property owned or operated by the colleges or universities referenced therein, or as may be directed by the chief law enforcement officer of the applicable county.   The prohibition of subsection (a) does not apply to official motor vehicles of a municipal police department being operated by reserve or auxiliary police officers duly authorized by the police chief and qualified pursuant to title 38, chapter 8. The reserve or auxiliary officers operating departmental vehicles shall be in uniform and carry appropriate identification issued by the police chief.    The prohibition in subsection (a) does not apply to any privately-owned motor vehicle that is primarily operated for business purposes by any salesperson, service representative, employee, lessee, or duly authorized agent of an emergency equipment company; provided, that the vehicle is marked with the lettering required by § 55-9-402(g)(3). Any person operating a motor vehicle pursuant to this subsection (f) shall comply with the requirements of § 55-9-402(g)(2).   Nothing in this subsection (f) imposes any duty or obligation on a manufacturer of motor vehicles used by or sold to emergency equipment companies to install, maintain or exhibit the lighting system allowed in this subsection (f) at the time of manufacture or sale.   Nothing in this subsection (f) shall be construed to permit the operator of an emergency equipment company vehicle from operating any lighting equipment authorized by subsection (a) while the vehicle is on a public road, whether in motion or stationary.   As used in this section, the terms “emergency equipment company” or “company” have the same meaning as defined in § 55-9-402.