FAQ

Frequently Asked Questions

What is a transponder?

A transponder is a small electronic device that attaches to the inside of the vehicle’s windshield and allows trucks to bypass weigh stations by electronically verifying the legal weight, safety rating and credentials of the truck.

Can I register my Transponder in other states?

Yes. Once a Transponder is purchased it is your property and can be registered for use in any NORPASS or PrePass jurisdiction as well as the Oregon Green Light system. Transponders registered with PrePass will be subject to PrePass regulations and fees.

Do I return my transponder if it’s no longer needed?

No. Once a transponder has been purchased it is your property.

Who do I call if I have problems?

Contact the Washington State Department of Transportation Transponder Administration at 1-888-877-8567.

What should I avoid doing when approaching a Weigh Station?
  • Excessive speed
  • Change of speed
  • Following too close to another vehicle
  • Lane changes
  • Excessive braking prior to reaching the Weigh-In-Motion scale (if applicable)
How can I prevent unnecessary Red Lights?
  • Center the Vehicle in the Weigh In Motion (WIM) lane (if applicable)
  • Maintain a steady legal highway speed
  • Provide at least a three second gap between your truck and other vehicles
  • Secure tarps so the wind does not trip the over-height detector
  • Avoid dark metallic window tinting that can interrupt the transponder signal
  • Avoid metallic windshield visors that can interrupt the transponder signal
  • Use only one transponder in your vehicle
  • CB’s may cause an interruption of the signal to the transponder
How much time will I save using a Transponder?

On average bypassing a weigh station saves 3-5 minutes.

Where do I place my Transponder at on the windshield?
  • Near the center of the windshield
  • On the passenger side of a divided windshield
  • Either three inches from the top or just above the dash board

Will my PrePass Transponder work in a NORPASS jurisdiction?

Yes.  NORPASS can register PrePass Transponders; however, the carrier must first contact PrePass.  NORPASS will only register a PrePass transponder upon receipt of a Letter of Authorization from PrePass.

Can I carry more than one Transponder in my truck?

It is not recommended. Having multiple transponders in a vehicle can prevent the correct one from being read.

Can I replace the battery in a transponder?

No. Removing the battery destroys the transponders memory.

Can I transfer a transponder to another vehicle?

Yes. Complete the Transponder Transfer form and fax it with a copy of the vehicle registration/cab card to the number provided on the form.