Can someone please tell me why, when parked for any period of time, some HGV drivers open the rear doors of their trailer? I have seen this a number of times, some trailers are empty, some are full of goods.
I doubt very much that you have seen it on a lorry full of goods. It is done so that potential thieves will not break into the lorry to get at what is inside - causing damage and cost to the vehicle. If the rear doors are open they can see that it is empty and will not break in.
Sometimes they are full of goods, but usually things that aren't likely to be nicked. eg 2 tonne rolls of paper, scrap plastic etc. When I used to have my artic, the worst 'attack' I had was in Birtley Truckstop nr Washington. Had scrap washing machines on and obviously the gits who broke in were so upset at having nothing to nick, they slashed my trailer curtains 8 times! Having paid �10 to stop there I was not best pleased. Cost over �100 for the repairs.