Quick Answer

Radar detectors are legal for use in private passenger vehicles in Massachusetts. However, they are illegal for commercial vehicles over 10,000 lbs and illegal to mount on the windshield if they obstruct your view.

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Radar Detector Laws in Massachusetts

Massachusetts takes a relatively straightforward approach to radar detector laws:

• Private Vehicles – You can legally own and use a radar detector while driving a standard passenger vehicle.
  
  
• Commercial Vehicles – Federal law prohibits radar detectors in vehicles weighing over 10,000 lbs, including in Massachusetts.
  
  
• Windshield Mounting – Massachusetts law prohibits placing any device that obstructs the driver’s clear view through the windshield. While this law isn’t radar detector-specific, mounting one in a way that blocks your view could result in a citation.
  
  

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Laser Jammers vs. Radar Detectors

• Radar Detectors – Detect radar signals used by law enforcement to measure speed.
  
  
• Laser Jammers – Designed to interfere with police lidar (laser) guns.
  In Massachusetts, laser jammers are illegal, as federal law prohibits actively interfering with police speed-measuring devices.
  
  

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Tips for Using Radar Detectors in Massachusetts

• Mount Smartly – Place your radar detector on the dashboard or low on the windshield to comply with visibility laws.
  
  
• Stay Alert – A radar detector isn’t a free pass to speed. It’s a tool to promote awareness, not a guarantee against tickets.
  
  
• Know the Signals – Familiarize yourself with the different alerts for radar bands and laser signals.
  
  

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Penalties for Illegal Use

If you’re caught with a radar detector in a commercial vehicle or using a laser jammer, you could face:

• Fines
  
  
• Equipment confiscation
  
  
• Potential points on your driving record
  
  

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FAQs – Radar Detectors in Massachusetts

Are radar detectors legal for passenger vehicles in Massachusetts?
Yes, they are legal for use in private passenger vehicles.

Can commercial drivers use radar detectors in Massachusetts?
No, commercial vehicles over 10,000 lbs cannot use radar detectors under federal law.

Can I mount my radar detector on my windshield?
Only if it doesn’t obstruct your view — otherwise, it could violate Massachusetts windshield obstruction laws.

Are laser jammers legal in Massachusetts?
No, laser jammers are prohibited under federal law.

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Final Thoughts

Radar detectors are legal for personal use in Massachusetts, but there are clear restrictions for commercial drivers and mounting locations. Always follow speed limits, stay aware of local laws, and use your detector as a tool for safer driving.

If you want a radar detector that’s easy to install and designed to keep your view clear, check out RoadSpy’s custom-fit mounting solutions.

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