Vermont Never Wrote a Radar Detector Rule, and the Commissioner Never Made One

Most states that ban radar detectors do it in a single sentence of the motor vehicle code, so the absence of that sentence is the finding here. Reading every chapter of 23 V.S.A. end to end, the code regulates windshield obstructions at § 1125, lighting devices at §§ 1243 through 1255, safety glass at § 1242, and inspection at §§ 1221 through 1231, and at no point does it mention a device that detects a speed measuring signal. The one place radar appears at all in Title 23 is 23 V.S.A. § 1605(3) and (9), which define an automated traffic law enforcement system and describe a vehicle that has "activated the radar component of an ATLE system" by travelling more than 10 miles above the speed limit. That is the enforcement side of the equipment, not the driver's side.

What makes the Vermont answer stable rather than accidental is § 1001. Subsection (a)(1) lets the Commissioner adopt rules relating to motor vehicle equipment in all cases where its use is not defined in the title, and where in the Commissioner's judgment use or nonuse contrary to the rules may render operation hazardous or unlawful. Subsection (a)(3) reaches any other matter that may hinder or impede the operator in the safe and careful operation of a motor vehicle, and (a)(4) allows rules in explanation of and in addition to, but not inconsistent with, the title. Subsection (c) requires any such rule to go through the full administrative procedure in 3 V.S.A. chapter 25, which means notice, a public comment period, and review by the Legislative Committee on Administrative Rules. So Vermont had a ready mechanism to ban detectors without amending a statute, and did not use it. The Periodic Inspection Manual, form VN-113 revision 3/2026, which is the Commissioner's own instrument for what a mechanic checks, contains no radar detector entry anywhere in its pleasure car, motorcycle, special vehicle, or heavy truck sections.

Commercial drivers are in a different position. 49 C.F.R. § 392.71 bars operating a commercial motor vehicle equipped with or using a radar detector, and Vermont plugs the federal motor carrier rules into state law through 5 V.S.A. § 2101. Subsection (e) authorises the Secretary of Transportation to adopt the Federal Motor Carrier Safety Administration regulations in 49 C.F.R. Parts 40, 350, 360, 365, 372, 381 to 383, 385 to 388, 390 to 397, and 399, as revised on 1 October 2008 and any amendment or addition to them. Part 392 sits inside that range. Subsection (a)(1) further requires the Secretary's rules to be no less protective of public safety than the federal rules, subsection (b) makes it unlawful to violate any rule adopted under the section, and subsection (c) caps the penalty at $1,000.00. Under subsection (d) such a violation may be charged on a traffic complaint prescribed by the Supreme Court under 4 V.S.A. § 1105, and 23 V.S.A. § 2302(a)(6) confirms that a violation of 5 V.S.A. chapter 29 and the rules adopted under § 2101 is a traffic violation. The adopting rule itself is published in the Code of Vermont Rules rather than in the statutes, so a commercial operator should treat the federal text as controlling and expect it to be enforced at a Vermont weigh station or roadside inspection.

Mounting is the one thing a private driver still has to get right, and it is governed by the windshield rules rather than by anything about detectors. 23 V.S.A. § 1125(a) prohibits material adhered on or over any transparent part of the windshield, the vent windows, and the side windows immediately left and right of the operator, and subsection (b) lists the only permitted items, among them a rearview mirror and an electronic toll-collection transponder located between the roof line and the mirror post or behind the mirror. A detector is not on that list, so a suction cup stuck to the glass is a violation even though the device itself is lawful. Section 1125(a) treats hanging items more leniently, prohibiting them only when the item materially obstructs the driver's view. A visor clip or a dashboard position keeps you clear of both branches.

One further Vermont detail matters for anyone assuming a detector is a defence: 23 V.S.A. § 1097 makes excessive speed a separate offence, and under 23 V.S.A. § 2502 speeding carries escalating points that feed the § 2505 suspension trigger at 10 points in a two-year period.

Owning, carrying, or using a radar detector in a private passenger vehicle in Vermont is not an offence, so there is nothing to enforce and no penalty to describe. Two adjacent rules do carry consequences. chapter 29. At the annual inspection required by § 1222, form VN-113 directs the mechanic to reject a vehicle when any nontransparent matter is present on the windshield outside the two permitted corner spaces, so a glass-mounted unit can also cost the sticker. § 2302(a)(6). Vermont's Commercial Vehicle Enforcement unit inspects at interstate weigh stations and on rural highways, so this is enforced in practice and not merely on paper.