What is the purpose of a Load Distribution Plan (Lastverteilungsplan) for a heavy rigid truck?

1. To determine the driving-and-rest schedule for the delivery route
2. To calculate only whether the total vehicle mass is below the registration value, without considering individual axles
3. To place the heaviest unit at the extreme rear whenever the cargo fits within the load bed
4. To determine how to place cargo along the longitudinal bed axis to ensure neither individual axle weight limits are exceeded nor the front steering axle becomes dangerously unloaded (maintaining minimum steering grip)