GB/T 19056 is the Chinese standard for vehicle travelling data recorders, the devices fitted to commercial vehicles, buses and hazardous goods vehicles that record speed, time, distance and other operating data and that are required by Chinese regulation for road transport management. The standard specifies the data that must be recorded and the accuracy with which each quantity is measured, the storage capacity and the protection of the stored data against loss and tampering, the interface used to read the recorder, and the display and printing requirements. Because the recorder is installed in the electrical environment of a vehicle and must keep functioning after a disturbance, the standard also sets requirements for its electrical behaviour and for its electromagnetic compatibility, including immunity to the transients produced on the vehicle supply and to electrostatic discharge, and it refers to the automotive test methods used for those verifications. Environmental requirements and the tests for mechanical and climatic robustness are included.