Out of Service is a legal status placed on a commercial vehicle or driver by a DOT inspector. If a safety check reveals critical violations, the inspector issues an OOS order. The truck is parked immediately and cannot be moved on public roads until the issues are repaired and verified. This is the most expensive outcome of a roadside check, as it halts the shipment.
Common reasons for a vehicle to be put out of service include worn brake pads, broken suspension parts, and flat tires. Drivers can also be placed out of service for hours-of-service violations, missing licenses, or medical cards. Violating an out-of-service order is a federal crime that leads to heavy fines, license suspension, and potential carrier shutdowns.