Is the vehicle left unattended in the parking lot properly protected against being started by unauthorized person?

In the photo you can see the inside of a lorry cab: the driver has gone, and a key with a key ring is in the ignition. A vehicle left unattended like this while parked is not properly protected against being started by an unauthorised person. The answer is: no.

The Road Traffic Act states that the driver of a vehicle is obliged, while parked, to protect the vehicle against being started by an unauthorised person and to take other precautions necessary to avoid an accident. A key in the ignition is an invitation: anyone who opens the door can start the engine and drive away in a lorry weighing more than ten tonnes - and someone who does not know how to drive it will cause an accident at the first junction. Protecting it means at least taking out the key, locking the doors and switching on the steering lock or immobiliser, and when parking for longer with a load, it is also sensible to choose a guarded car park. A lorry driver is also responsible for the load and for making sure that the vehicle does not roll away: you apply the parking brake, and on a slope you put chocks under the wheels. Leaving the key "for a moment" is a petty offence, whether or not anyone took advantage of it.

Legal basis: Art. 46 para. 5 of the Road Traffic Act (Prawo o ruchu drogowym)