Indiana Radar Detectors: Legal in Cars, and Jammers Became a Felony in 2025

The negative here is provable rather than assumed. The Indiana General Assembly publishes the complete Indiana Code as a downloadable set of 36 HTML title files, so the whole corpus can be searched at once. The word radar appears nine times in the 2026 edition. One is the signal jammer definition at Ind. Code § 35-45-2-6. Two are in the public pension divestment definitions of military equipment at Ind. Code § 5-10.2-9-13 and § 5-10.2-10-10.2, which list radar systems. Four are in the signal interference sections of the wind and solar siting statutes, Ind. Code § 8-1-41-12 and § 8-1-42-15, which protect military defense radar and weather and doppler radar. One is the definition of a precision instrument runway at Ind. Code § 8-21-10-8, and one is the worksite speed control system definition at Ind. Code § 8-23-32-7, which describes a radar device used by the state to record speeds rather than by a driver to detect them. The word detector appears in the Code only in connection with smoke detectors and metal detection devices. No Indiana statute makes a detector contraband, forfeitable, or a basis for a citation, and none appears in Article 9-19, the motor vehicle equipment article where such a prohibition would sit.

The device Indiana does prohibit is the jammer, and the prohibition is recent. Ind. Code § 35-45-2-6 was added by P.L.183-2025, SEC.4, and defines a signal jammer as a device designed to intentionally block, jam, or interfere with licensed or authorized radio communication, expressly including devices that interfere with personal communications services, police radar, GPS, and wireless networking services. Subsection (b) reaches two separate courses of conduct: manufacturing, offering for sale, importing, marketing or selling a jammer, and simply possessing, using or operating one. Possession alone completes the offence, so a jammer sitting unused in a glovebox is enough. That is the line an Indiana driver needs to understand: a detector listens to a police signal and is unregulated, while a device that degrades that signal is a felony.

Commercial vehicles are the one place Indiana law bans detectors, and it does so by reference rather than by its own words. Ind. Code § 8-2.1-24-18(a) incorporates 49 CFR Parts 40, 375, 380, 382 through 387, 390 through 393, and 395 through 398 into Indiana law by reference, and requires compliance by an interstate and intrastate motor carrier of persons or property throughout Indiana. Part 392 falls inside that range, and 49 CFR 392.71(a) 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, while 392.71(b) forbids a motor carrier to require or permit a driver to violate that rule. Because Indiana adopted the federal parts for intrastate carriers as well, a truck running only between Fort Wayne and Evansville is bound by the same rule as one crossing the state line.

Mounting is the remaining constraint on a lawful detector. A unit suction-cupped to the glass is nontransparent material on a windshield, and Ind. Code § 9-19-19-3(b) prohibits driving with a sign, poster, sunscreening material or other nontransparent material on the windshield, side wings, or side or rear windows that obstructs the driver's clear view of the highway or an intersecting highway. The one safe harbour is material not larger than four inches square placed in the lower corner farthest removed from the driver. Indiana's hands free law does not reach a detector: Ind. Code § 9-21-8-59 applies to a telecommunications device, and Ind. Code § 9-13-2-177.3 defines that term as a wireless telephone, personal digital assistant, pager or text messaging device intended for handheld use, or a wearable device that blocks the field of vision.

Nothing happens to an Indiana motorist for owning or using a radar detector in a private passenger vehicle, because no provision of the Indiana Code prohibits it. Unlawful use of a signal jammer under Ind. Code § 35-45-2-6(c) is a Level 6 felony, punishable under Ind. Code § 35-50-2-7(b) by a fixed term of between six months and two and one half years, with an advisory sentence of one year, plus a fine of up to $10,000. Under Ind. Code § 35-45-2-6(d) the offence rises to a Level 5 felony where the jammer is used to disrupt a component of a critical infrastructure facility or the communications of a public safety agency as defined in Ind.

5-1-5, carrying one to six years under Ind. Code § 35-50-2-6(b), with an advisory sentence of three years and the same $10,000 maximum fine. A commercial driver found with a detector violates a federal rule adopted as Indiana law by Ind. 1-24-18(a), enforced through Indiana State Police roadside compliance checks and the compliance review criteria set by the superintendent in the same section. Obstructing the windshield with a badly placed mount is a Class C infraction under Ind. Code § 9-19-19-7(b), a judgment of up to $500 under Ind. Code § 34-28-5-4(c).