The legality of radar detectors is a common question for drivers, as rules can vary based on vehicle type and jurisdiction. This article analyzes the laws governing the use of radar detectors for drivers in South Carolina, clarifying where and when their use is permitted.
Radar Detector Legality in South Carolina Private Vehicles
In South Carolina, the law permits the use of radar detectors in private passenger vehicles, including cars and motorcycles, as no state statute outlaws their possession or operation. This means drivers of private vehicles are not in violation of state-level traffic laws by using one. It is important, however, that the placement of the device does not obstruct the driver’s view of the road.1Justia. South Carolina Code Section 56-5-5000 (2024) – Windows Unobstructed; Windshield Wipers.
South Carolina Specific Prohibitions and Limitations
While radar detectors are permissible in private cars, South Carolina law places explicit restrictions on their use in commercial vehicles. The South Carolina Code of Regulations forbids the use of a radar detector in a commercial motor vehicle. The rule states that no driver shall use a radar detector in a commercial motor vehicle or operate one that is equipped with such a device.2Justia. South Carolina Code of Regulations, Section 38-392.71 – Radar Detectors; Use and/or Possession Furthermore, it prohibits a motor carrier from requiring or permitting a driver to violate this rule, placing responsibility on both the driver and their employer.
Federal Rules on Radar Detectors Applicable in South Carolina
Beyond state rules, federal regulations from the Federal Motor Carrier Safety Administration (FMCSA) also ban radar detectors in commercial motor vehicles (CMVs). This nationwide mandate states that a CMV cannot be operated if it is equipped with or contains a radar detector.3Electronic Code of Federal Regulations. 49 CFR 392.71 — Radar Detectors; Use and/or Possession. A CMV is defined as a vehicle used in commerce with a gross vehicle weight rating of 10,001 pounds or more. The definition also includes vehicles designed to transport more than eight passengers for compensation, or more than 15 passengers regardless of compensation. Additionally, federal law prohibits the use of radar detectors on all U.S. military installations.
Radar Jammers Distinguished from Detectors
A radar detector must be distinguished from a radar jammer. A detector is a passive receiver that alerts a driver to police radar signals, while a jammer is an active transmitter designed to interfere with or block law enforcement signals. Under the federal Communications Act of 1934, radar jammers are illegal to manufacture, sell, or use in any state.4Legal Information Institute. 47 U.S. Code § 333 – Willful or Malicious Interference South Carolina also has its own statute making it unlawful for any vehicle to be equipped with a device designed for jamming police radar or laser.
Consequences of Violating Radar Device Laws
Penalties for unlawfully using a radar device in South Carolina depend on the device and vehicle. For a commercial vehicle driver caught with a radar detector, the consequences include federal civil penalties that can impact both the driver and the motor carrier.5Federal Motor Carrier Safety Administration. Revisions to Civil Penalty Amounts, 2025 The use or possession of a radar or laser jammer carries more severe penalties. A violation of South Carolina’s law is a misdemeanor that can result in a fine.6Justia. South Carolina Code Section 56-5-3870 (2024) – Motor Vehicle Speed Detection Jamming Devices. Federal penalties for using a jammer are stricter and can lead to substantial fines and even imprisonment.