What 392.71A means in plain language
FMCSR 392.71A prohibits the use or installation of radar detection equipment on a commercial motor vehicle. This includes any device designed to detect or warn of police radar, laser, or speed enforcement technology.
The regulation applies to the vehicle itself and to the driver operating it. Whether you personally own the detector, it came pre-installed by the carrier, or a dispatcher instructed you to use it, the citation falls on the vehicle and driver combination at the time of inspection.
Radar detectors are prohibited because they're considered incompatible with the safe operation of commercial trucks. Federal safety rules prioritize compliance with posted speed limits and traffic laws over driver preference for early warning of enforcement.
What our enforcement data actually shows
Across 13 million+ inspections in our database, 392.71A has generated 508 all-time citations, with 271 citations in the last 12 months and 54 in the last 90 days. This ranks 392.71A at #914 out of 3,036 FMCSR codes by citation volume—a relatively uncommon violation.
The critical enforcement characteristic: zero out-of-service placements. Our data shows a 0.0% OOS rate for this code across all time. Not a single vehicle has been placed out-of-service for a 392.71A violation. This contrasts sharply with the all-FMCSR average OOS rate of 31.4%, meaning 392.71A citations do not typically result in immediate removal from service.
Monthly trends show seasonal variation. The last 12 months peaked in February 2026 with 34 citations, and June 2025 with 31 citations. April 2026 recorded only 1 citation, suggesting either a natural low-enforcement month or a reporting lag.
Who gets cited most
Our inspection records show three states account for the bulk of 392.71A enforcement in the last 180 days:
- Texas: 39 citations, 0 OOS placements (0.0% rate)
- New Mexico: 34 citations, 0 OOS placements (0.0% rate)
- Iowa: 25 citations, 0 OOS placements (0.0% rate)
North Carolina (9 citations) and Illinois (8 citations) round out the top five. The OOS rate is uniform across all top states at 0.0%, indicating consistent enforcement philosophy regardless of geography—citations are issued, but vehicles are not removed from service.
By carrier, our data shows fleets such as United Parcel Service Inc with 5 all-time citations and Speed Intermodal with 3 citations. These numbers reflect the scale of these operations and enforcement frequency; they do not indicate systemic non-compliance compared to smaller carriers.
How severe is this compared to similar codes
392.71A sits in the Unsafe Driving category alongside codes that carry far greater enforcement weight. For comparison:
- 392.2 (Operating a CMV while ill or fatigued): 1,208,164 citations with a 0.8% OOS rate. This is roughly 2,400 times more common than 392.71A.
- 392.2RG (Operating a CMV while ill or fatigued, regional variant): 96,652 citations with a 0.1% OOS rate—still nearly 190 times more frequent.
- 392.2-SLLEWA1 (Operating while ill or fatigued, specific circumstance): 69,565 citations with a 1.0% OOS rate.
The enforcement disparity reveals that 392.71A is treated as a lower-priority safety violation within the Unsafe Driving category. Fatigue and illness violations vastly outpace radar detector citations in enforcement volume and OOS action.
How to avoid it
The straightforward prevention step: remove any radar detection device from your vehicle before operating it as a CMV. This includes hardwired units, temporary plug-in devices, and smartphone apps that function as radar detectors.
Our inspection data also reveals common co-occurring violations that point to broader vehicle and operational issues:
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Inoperable lamps (393.9) and window obstructions (393.60D) co-occur in 13 and 10 inspections respectively. Conduct a pre-trip walk-around: verify all exterior lights function, check windshield and windows are clean and unobstructed, and ensure no aftermarket equipment (including detectors) is mounted where it blocks sightlines.
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Missing or defective emergency equipment (393.95A, 393.95F) appears in 7 and 6 co-occurring inspections. A vehicle that lacks fire extinguishers or warning devices is also more likely to have contraband equipment like radar detectors. Verify your emergency kit is complete and accessible during pre-trip.
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Operating without a valid CDL (383.23A2) and operating without proof of periodic inspection (396.17C) each co-occurred in 8 inspections. These suggest that enforcement encounters capturing 392.71A often involve vehicles with compounding compliance gaps. Keep your CDL valid, your medical certificate current, and your vehicle inspection records current.
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Tire defects (393.75A3) appeared in 4 co-occurring inspections. Poor tire condition can trigger a roadside inspection that would not otherwise occur, increasing the likelihood of detection of a radar detector if one is present.
By vehicle type, our data shows citations across diverse makes: PTRB (108), FRHT (105), and UTIL (72) models lead. This breadth indicates radar detectors appear across all truck types and configurations. Equipment removal applies universally, regardless of your vehicle make or year.
Bottom line for drivers: A 392.71A citation will not remove you from service immediately, but it is a violation on your record and may affect your carrier's safety rating. The easiest prevention is simple: don't carry or use radar detection equipment in a commercial vehicle.