Driving and Vehicle Operation, Supervision and Parking
Driving behaviour
Dangerous goods vehicles must be driven smoothly: no harsh braking, no sharp cornering, and reduced speed where required. The driver must observe national speed limits and any special restrictions for dangerous goods. Overtaking should be minimised. Traps: assuming ADR sets a single European speed limit - it does not; national rules and vehicle approval apply.
Supervision
A vehicle carrying dangerous goods must not be left unattended unless the load is secured, the vehicle is locked, and parking rules are met. In some cases a supervisor is required. The driver must keep the vehicle in sight or within reach when supervision is required. A frequent trap: leaving the vehicle to buy fuel or coffee with the load unsecured.
Parking
Parking must be in a safe place, away from residential buildings, bridges, tunnels and crowded areas where possible. Where required, the vehicle must be parked in a designated area. The parking brake must be applied, and where required, wheel chocks used. Traps: parking under a bridge or in a tunnel, and parking near a source of ignition.
Worked rule of thumb
If you must leave the vehicle, apply the "secure, lock, supervise" test: is the load secure, is the vehicle locked, and can you still supervise it? If any answer is no, move the vehicle or do not leave it.