Weigh Stations & Inspection Sites

Weigh stations and inspection sites are fixed and mobile facilities operated by state law enforcement agencies under the Motor Carrier Safety Assistance Program (MCSAP). MCSAP is a federal grant program that funds state enforcement of federal motor carrier safety regulations. Inspections may be conducted at permanent weigh stations, portable scales set up at roadsides, or during targeted enforcement operations.

What Happens at a Weigh Station

When a commercial vehicle enters a weigh station, it may be subject to several types of checks:

• Weight checks: Vehicles are weighed on static or weigh-in-motion scales to verify compliance with federal and state weight limits.
• Credential checks: Officers verify the carrier's USDOT number, operating authority, insurance, registration, and driver qualifications.
• Safety inspections (Levels I–VI): Inspections range from a comprehensive Level I (full vehicle and driver inspection) to a Level VI (enhanced inspection for radioactive materials). The most common are Level I, Level II (walk-around driver/vehicle), and Level III (driver-only).

PrePass & Bypass Programs

Electronic screening programs like PrePass and Drivewyze allow qualifying carriers to bypass weigh stations without stopping. These systems use transponders or mobile apps to identify approaching vehicles, check their safety record and credentials in real time, and signal a green light for bypass or a red light requiring the vehicle to pull in. Carriers with good safety records and current credentials are bypassed at high rates, saving time and fuel.