Delaware Bans Radar Detectors Only in Commercial Trucks

The absence of a passenger-car ban is structural, not an oversight. A full-text reading of Title 21 turns up the word radar exactly twice, and both times it is about how the State proves speed rather than how a driver may respond to it. 21 Del. C. § 701(a)(2) lets a uniformed officer arrest without a warrant for a § 4169 speed violation "when the speed is determined by radar, electronic devices, electromechanical devices, audio sensor devices, visual sensor devices or aerial spotting," even though the arresting officer did not personally observe the radar speed meter, provided that officer is positioned to observe the vehicle being detected, is working with the reading officer, and is immediately advised of the violation. 21 Del. C. § 706(b) then directs that fines and costs collected as a result of radar or other speed timing devices, where the device is operated beyond the corporate limits of a city or town but within extended corporate limits under a municipal charter, be paid to the State Treasurer for the General Fund. Delaware legislates about the officer's radar; it does not legislate about the driver's detector.

That silence is meaningful because the General Assembly has shown it will name an electronic countermeasure when it wants one banned. 21 Del. C. § 4112A(a) defines a "traffic control signal preemption device" as any device emitting a pulse of light or other signal that, when received by a detector attached to a traffic control signal, alters or interferes with the normal operation of the traffic control device. Section 4112A(b) then prohibits installing one on a motor vehicle, transporting one in the passenger compartment, and operating one as driver or passenger. Violation is an unclassified misdemeanour, the device is seized on arrest and forfeited on conviction, and the fine is not less than $250 nor more than $750, with up to 3 months at Level V. Selling one for an unpermitted purpose is a class A misdemeanour under § 4112A(c), which 11 Del. C. § 4206(a) puts at up to 1 year and a fine up to $2,300. Six categories of vehicle keep the device under § 4112A(d), including law-enforcement, fire, ambulance, organ transport and Delaware Emergency Management Agency vehicles responding to a bona fide emergency with sirens or flashing lights, and Department of Transportation signal-repair vehicles. A radar detector appears in none of this, and no parallel section exists for it.

The commercial rule is real and enforceable in Delaware, so drivers of larger vehicles should not read the passenger-car answer across. Chapter 47 of Title 21 is the Delaware motor carrier safety chapter, and § 4702(a) adopts Parts 374, 385, 386, 387, 390, 391, 392, 393, 395, 396 and 397 of 49 C.F.R. Chapter III, Subchapter B "as published and as subsequently amended." Delaware then amends only two things in Part 392, both in § 4705: it adds a subparagraph to 49 C.F.R. § 392.4 and another to § 392.5, each saying that nothing in those sections precludes prosecution under 21 Del. C. § 4177, the driving-under-the-influence statute. Section 392.71, the radar detector prohibition, is adopted without alteration. Section 4714(a) reinforces the point from the other direction: additional equipment and accessories are permitted only if "not inconsistent with or prohibited by this chapter" and only if they do not decrease the safety of operation.

Section 4702(b) is where a Delaware answer diverges from a bare recitation of the federal rule. In intrastate commerce, chapter 47 does not reach a single vehicle or combination with a gross vehicle weight rating or gross vehicle weight of 26,000 pounds or less, with two exceptions that pull smaller vehicles back in: a vehicle transporting hazardous materials of a type or quantity requiring marking or placarding under the Federal Motor Carrier Safety Regulations, and a vehicle with a seating capacity of 16 or more persons. A contractor's pickup running purely inside Delaware under 26,000 pounds is therefore outside the chapter and outside the detector ban; the same pickup placarded for hazardous materials is inside it.

For a passenger car there is no offence, so there is nothing to enforce. For a vehicle inside chapter 47, 21 Del. 75 nor more than $115 for each violation, or imprisonment for not more than 30 days, or both. A second or subsequent offence within 2 years carries a fine of not less than $115 nor more than $575 or imprisonment for not less than 60 days nor more than 1 year, or both. Section 4710 separately gives authority to place a vehicle, driver or motor carrier out of service, which is the practical consequence at a roadside inspection.

On the preemption-device side, § 4112A(b) attaches seizure on arrest and forfeiture on conviction to the fine of $250 to $750 and up to 3 months at Level V, and § 4112A(c) makes the sale a class A misdemeanour. Speed enforcement itself is governed by 21 Del. § 701(a)(2), which authorises a warrantless arrest on a radar reading taken by a second officer, so a detector that warns of one unit does not defeat a two-officer setup.