Because the petrol station has to shut while petrol deliveries are made so they want deliveries off peak as in the middle of the night. Plus the reduction in traffic at night saves diesel. A few quid extra for the driver per hour is the smallest add on cost. Loads of European drivers have German and French ADR qualifications so its not a skill that’s scarce.
Back in the day when oil companies were “in house” the job was very well paid, however like lots of companies have gone to the likes of Hoyer and Wincanton and so on the money and the T&C’s have gone down the pan.
If I see someone driving a truck like a madman that usually speaks volumes to me, the same money or more can be made elsewhere with a fraction of the stress.
I held an ADR, I never once used it and I didn’t renew nor will I.
Better safer work about, less stress, better start times and no rushing about for the same money, you may be lucky and get a very good little number but that’s unlikely.