Kentucky Bans Radar Detectors Only in Commercial Trucks, Through an Adopted Federal Rule

The absence of a passenger-car ban in Kentucky is provable rather than assumed. KRS Chapter 189 is titled Traffic Regulations, Vehicle Equipment and Storage, and it is where the Commonwealth puts every equipment rule it has: windshields and sunscreening in KRS 189.110, safety glass in KRS 189.120, mirrors in KRS 189.130, horns and sound devices in KRS 189.080, tire chains and lugs in KRS 189.190, and the catch-all in KRS 189.020 that every vehicle on a highway be equipped to make a minimum of noise, smoke or other nuisance. Read end to end, all 211 sections of that chapter use the word detector zero times and the word radar exactly once, and that single use is in KRS 189.2326(1)(a), which defines an automated speed enforcement device for highway work zones as a photographic, radar, lidar, laser or other device with vehicle sensors that transmits a vehicle's speed and an image of the rear licence plate. Kentucky legislated about the radar the state points at you, not the receiver you buy.

The commercial ban comes in by adoption rather than by drafting. 601 KAR 1:005, the Transportation Cabinet's safety administrative regulation, is promulgated under KRS 281.600, KRS 174.410(2) and related sections, and Section 2 declares that a commercial motor vehicle and its operator meeting the definitions in 49 C.F.R. 390.5, whether operating for-hire or in private carriage and whether interstate or intrastate, shall be governed by thirteen listed federal parts. Item (8) on that list is 49 C.F.R. 392, Driving of Commercial Motor Vehicles. Inside that part, 49 C.F.R. 392.71 is headed Radar detectors; use and/or possession, and 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. Possession inside the cab is enough; the device does not have to be switched on.

Whether you are caught by that turns on the federal definition Kentucky borrowed. Under 49 C.F.R. 390.5 a commercial motor vehicle is one with a gross vehicle weight rating or gross combination weight rating, or actual gross weight, of 4,536 kg (10,001 pounds) or more, whichever is greater; or designed or used to carry more than 8 passengers including the driver for compensation; or more than 15 passengers including the driver not for compensation; or used to transport hazardous material in a placardable quantity. A pickup, a work van or a car-hauler that crosses 10,001 pounds rated weight is inside the rule even on a purely Kentucky route, because 601 KAR 1:005 Section 2 says intrastate in terms.

Kentucky then carves out its own public fleets. Section 4(1)(a) of the same regulation provides that a motor vehicle operated by the federal government, a state government, a county government, a city government or a board of education is not required to comply with the federal regulations adopted in the regulation, with two exceptions in paragraphs (b) and (c): a driver required by KRS Chapter 281A to hold a commercial driver's licence must show a passed 49 C.F.R. 391 medical examination or a waiver under 601 KAR 11:040, and the operator must meet the 49 C.F.R. 382 drug and alcohol testing requirements. Neither exception carries Part 392 with it, so the adopted radar-detector prohibition does not reach a Kentucky school board bus or a county or city truck. Section 4(2) separately lets an intrastate Kentucky commercial driver be eighteen rather than the federal twenty one, and Section 4(4) requires a carrier operating exclusively in intrastate commerce, other than farm-to-market agricultural transportation rated at 26,000 pounds or less, to obtain an intrastate USDOT number on Form MCS-150 and display it preceded by the letters USDOT and followed by the letters KY.

One practical Kentucky limit applies even to a lawful detector in a private car: where you stick it. KRS 189.110(2) prohibits operating a motor vehicle with any sign, product or covering attached to or located in or upon the windshield except three listed things, which are a certificate or paper required to be displayed by law, a transparent strip of sunscreening material at the top of the windshield that stays out of the AS/1 viewing area, and sunscreening material of at least 70 percent light transmittance that is not red or yellow. A suction-cupped radar detector is none of those. Mounting it on the dash or clipped to a visor keeps it off the windshield and out of that closed list.

The consequences split by vehicle class. In a private Kentucky car there is no offense at all for carrying or using a detector, and no fine to attach, because no statute or regulation prohibits it. 990(1)(a) applies: a person who violates, causes, aids or abets any violation of the chapter or of any order, rule or administrative regulation lawfully issued under it shall be fined not less than twenty five dollars and not more than two hundred dollars. The same subsection adds that every device to evade or prevent the application of a provision of the chapter or of a lawful regulation of the department is itself a violation.

R. 71(b), as adopted, also puts the carrier on the hook, because no motor carrier shall require or permit a driver to violate the detector prohibition, so a Kentucky fleet that leaves detectors in its cabs is exposed alongside the driver. Enforcement is roadside and at commercial inspection, not on a schedule: Kentucky runs no periodic safety inspection for ordinary vehicles, and the Legislative Research Commission's own KAR index for Title 601 marks Chapter 010, Motor Vehicle Inspection, as Inactive. 990(1)(a) punishes by a fine of not less than twenty dollars and not more than one hundred dollars per offense.