Radar Detector Laws in Massachusetts

• Private Vehicles: Legal to own and use a radar detector in a standard passenger vehicle.
• Commercial Vehicles (>10,000 lbs): Prohibited under federal rules; this includes operation in Massachusetts.
• Windshield Mounting: Massachusetts law prohibits placing devices that obstruct the driver’s clear view. Mount detectors so they do not block visibility.

Note: Laws and enforcement guidance can change. Always verify current rules with official state resources.

Radar Detectors vs. Laser Jammers

Radar Detectors

• Passive devices that detect radar signals used by law enforcement to measure speed.
• Legal for private passenger vehicles in Massachusetts (see commercial vehicle exception above).

Laser Jammers

• Active devices designed to interfere with lidar (laser) guns.
• Not legal to use; interfering with police speed-measuring devices is prohibited.

Tips for Using Radar Detectors in Massachusetts

• Mount smartly: Use a low, non-obstructive position (e.g., dashboard) so your view remains clear.
• Stay alert: A detector is an awareness tool, not a license to speed. Always follow posted limits.
• Know your signals: Learn the common radar bands (X, K, Ka) and laser alerts your device provides.
• Minimize distractions: Configure GPS lockouts or smart filtering to reduce false alerts.

Penalties for Illegal Use

If you’re cited for prohibited use—such as operating a radar detector in a commercial vehicle or using a laser jammer—you may face:

• Fines and potential equipment confiscation
• Possible points or penalties per applicable regulations

Exact penalties vary. Check current Massachusetts and federal rules for details.

Final Thoughts

Radar detectors are legal for personal use in Massachusetts, but there are clear restrictions for commercial drivers and for how you mount your device. Use your detector to stay aware, follow posted speed limits, and keep your view unobstructed.