DVIR stands for driver vehicle inspection report. Drivers are supposed to check their vehicle before and after driving to make sure everything is in order.
Property carrying vehicles:
A formal DVIR is only required when a vehicle issue/defect is reported to the driver or found by the driver. If a defect is found, the driver must fill out a report, sign it and have a mechanic sign off on the report once the repair is made.
Passenger carrying vehicles:
A formal DVIR is required regardless of whether a defect is found or not.