South Carolina Radar Detectors: Legal in Cars, Banned in Big Rigs

The starting point is what South Carolina never enacted. A full-text search of the Code of Laws on the General Assembly site returns no matches at all for the phrase radar detector, and a search on the single word radar returns three documents across the entire Code: the jamming section at 56-5-3870, the bar on photographic speed enforcement in Section 56-5-710(B), and one document outside Title 56. There is no registration, equipment-approval or possession offense to be found, and Section 56-5-4430 supplies the positive rule for accessories generally: nothing in the equipment article shall be construed to prohibit the use of additional parts and accessories of any vehicle which are not inconsistent with the provisions of that article. A device that only listens is not inconsistent with anything in the article.

What is banned is the active device. Section 56-5-3870, added by 2006 Act No. 279 with effect from May 23, 2006, has two limbs, and the first catches the car rather than the driver: it is unlawful for a motor vehicle to be equipped with such a device, whether or not it is switched on, and separately unlawful for an operator to employ one. The banned function is described broadly, covering anything designed for jamming, scrambling, neutralizing, disabling or interfering with radar, laser, or any other electronic device used by a law enforcement agency to measure the speed of a motor vehicle. The words laser and any other electronic device matter, because they take in the modern laser jammer and shifter as squarely as an old radar scrambler. The distinction the statute draws is between receiving a signal and acting on it. A passive detector that reports the presence of a K-band or Ka-band emission does nothing to the police unit and falls outside subsection (A); a jammer that returns a signal in order to defeat a lidar reading is inside it.

Commercial drivers face a flat prohibition instead. South Carolina Code of Regulations 38-392.71, promulgated by the Department of Public Safety, provides that no driver shall use a radar detector in a commercial motor vehicle, or operate a commercial motor vehicle that is equipped with or contains any radar detector, and that no motor carrier shall require or permit a driver to violate that rule. The definition in Regulation 38-390.5 is deliberately wide, reaching any device or mechanism to detect the emission of radio microwaves, laser beams or any other future speed measurement technology employed by enforcement personnel, and it excludes a detector only where it is both transported outside the driver compartment and completely inaccessible to, inoperable by, and imperceptible to the driver while operating the vehicle. Stowing the unit in the sleeper is not enough on its own.

Who that reaches is set by Section 56-5-4240. A commercial motor vehicle and its driver operating in intrastate commerce at a gross vehicle weight, gross vehicle weight rating, gross combination weight or gross combination weight rating of 26,001 pounds or more must meet the Federal Motor Carrier Safety Regulations, and subsection (B) exempts commercial vehicles operating below 26,001 pounds. Two classes lose that weight exemption under subsection (C): a vehicle designed or used to transport sixteen or more passengers including the driver, and a vehicle used to transport hazardous materials requiring placards under 49 C.F.R. part 172, subpart F. Regulation 38-390.3(a) applies the rules to employers, employees and commercial motor vehicles transporting property or passengers in intrastate commerce.

One practical point about where the detector sits. South Carolina has no periodic vehicle safety inspection, so there is no lane at which a detector would ever be seen, but a unit suction-cupped to the glass still has to satisfy Section 56-5-5000, which forbids driving with any sign, poster or other nontransparent material upon the front windshield, sidewings or side or rear windows that obstructs the driver clear view of the highway or any intersecting highway. That is the only realistic exposure for an ordinary motorist using a detector here.

The wider enforcement picture explains why detectors remain relevant in this State. South Carolina has effectively closed the door on automated speed enforcement. Section 56-5-710(B) says nothing in the local-authority powers section permits a local authority to issue a uniform traffic citation for speeding or disregarding traffic control devices based in whole or in part upon photographic evidence, whether or not gathered in conjunction with radar speed detection devices and whether the capturing device was attended or unattended. Section 56-5-70(E) allows a photographic-evidence citation only for violations occurring while federal regulatory relief under 49 C.F.R. 390.23 has been granted due to an emergency, and even then the driver must be served in person within one hour. Speed in South Carolina is measured by an officer with a hand-held or vehicle-mounted unit, which is exactly what a detector is built to hear.

A jamming device is a misdemeanor under Section 56-5-3870(B) punishable by a fine of not more than one thousand dollars, with no term of imprisonment prescribed. That maximum sits above the cap in Section 56-5-6150, which lets a municipal court try a Chapter 5 offense only where the penalty prescribed does not exceed thirty days imprisonment or a one hundred dollar fine, so the charge belongs in magistrate court. The offense does not appear anywhere in the twenty-eight item point schedule in Section 56-1-720, so a conviction adds no points toward the twelve that trigger a suspension under Section 56-1-740.

Under Section 56-5-6200 the fine is paid to the county treasurer, or the city treasurer where a municipal officer collected it. C. Code Section 58-23-1120 or other related statutes, and that section gives the Transport Police Division of the Department of Public Safety exclusive authority in this State for enforcement of the commercial motor vehicle carrier laws, including the Federal Motor Carrier Safety Regulations. A radar detector found in a truck cab at a weigh station is therefore a carrier-safety matter handled by Transport Police, not an ordinary traffic ticket.