Illinois Bans Radar Detectors Only in Commercial Vehicles

Illinois legislated detectors and jammers twenty years apart and drew the line in different places. Section 12-714, added by Public Act 90-89 effective January 1, 1998, is headed "Possession and use of radar detection devices prohibited" but its reach is narrow: it applies only to a commercial motor vehicle as that term is defined in Section 6-500(6) of the Code. That definition, part of the Uniform Commercial Driver's License Act, covers a vehicle used in commerce with a gross combination weight rating of 26,001 pounds or more, or a gross vehicle weight rating of 26,001 pounds or more, or one designed to transport 16 or more persons including the driver, or a vehicle of any size transporting hazardous materials as defined in 49 C.F.R. 383.5. Recreational vehicles operated primarily for personal use are expressly outside it. A commuter car, a pickup, a minivan and a personal RV therefore fall outside section 12-714 entirely, and nothing else in the Vehicle Code prohibits owning, mounting or using a detector in one.

Section 12-613, added by Public Act 94-594 effective January 1, 2006, works the other way round. It prohibits any person from operating or being in actual physical control of a motor vehicle equipped with an instrument designed to interfere with microwaves or lasers at the frequencies used by police radar for the purpose of monitoring vehicular speed. There is no weight threshold and no commercial limitation, so a laser jammer or radar jammer is unlawful in a family sedan in Illinois even though a detector in the same car is not. The distinction is between a device that listens and a device that interferes.

Both sections contain the same safe harbour, and it matters for a driver moving equipment rather than using it. A person is not in violation if the device is contained in a locked opaque box or similar container, or is not in the passenger compartment, and in either case is not in operation. A jammer boxed in the trunk of a car and a detector boxed in a semi tractor's sleeper are both outside the offense.

The seizure rules are where the two sections diverge again, and section 12-613 is harsher. Under 12-613(d), the jammer is seized by the officer at the time of the violation, on a first offense. Under 12-714(c), the detector is seized only if the offender has previously been convicted under that section. Neither section authorises permanent forfeiture to the State. The device is held only for the period it is needed as evidence, after which the defendant may petition the court for its return, and the defendant must prove by a preponderance of the evidence that the device will be used only for a legitimate and lawful purpose.

The stop protection is the most practical part of both sections for a driver. Section 12-714(d) states that no commercial motor vehicle, and no driver of one, shall be stopped or searched by any law enforcement officer solely on the basis of a violation or suspected violation of that section, and 12-613(e) says the same for jammers as to any motor vehicle or driver. A suction-cupped box on the windshield is not, standing alone, a lawful basis for the stop. Illinois wrote the same clause into the windshield-obstruction subsection at 625 ILCS 5/12-503(c-5), but pointedly did not write it into the tint subsections, so the protection is provision-specific rather than a general rule about equipment stops.

A violation of either section is a petty offense. 5-75(a): a fine not to exceed $1,000 for each offense or the amount specified in the offense, whichever is less. A petty offense carries no term of imprisonment. Neither offense is written as a moving violation with points attached, and the practical consequence in a commercial case is the loss of the detector, which is seized under 12-714(c) once there is a prior conviction. A jammer is seized under 12-613(d) at the time of the first violation.

Getting either device back requires a petition to the court and proof, by a preponderance of the evidence, that it will be used only for a legitimate and lawful purpose. Because the enforcement bar in 12-714(d) and 12-613(e) blocks a stop made solely on suspicion of these offenses, a charge normally arises out of a stop or inspection that was already lawful for another reason.