49 CFR 392.71

The Federal Motor Carrier Safety Regulations, at 49 C.F.R. §392.71, on Radar Detectors, mandates:

(a) 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.

(b) No motor carrier shall require or permit a driver to violate paragraph (a) of this section.

This regulation is rarely discussed in court decisions.

Even if a radar detector seized by police were excluded from evidence in a criminal trial of the truck driver, it likely would be admissible in a civil trial for damages. In one Pennsylvania criminal case, the court held that a warrantless seizure of radar detector, which a police officer viewed through commercial tractor-trailer's windshield as he stood on public highway, was justified under plain view doctrine, even though seizure was delayed until time when truck was impounded. A radar detector that defendant had mounted in his vehicle was admissible, despite being evidence of prior bad act, in prosecution for homicide by vehicle, where the prosecution relied on the radar detector to show  a defendant's intent to violate speed restrictions in order to demonstrate that defendant's conduct was criminally negligent or reckless.  Com. v. Petroll, 696 A.2d 817, Super.1997, appeal granted in part 703 A.2d 1034, 550 Pa. 167, affirmed 738 A.2d 993, 558 Pa. 565 (1999).