Pre EU foreigners could come over here drop off, do one cabotage trip then pick up a load and leave we could do the same. After the borders opened EU drivers could do unlimited interior trips, as could we which wasn't a problem at first as there wasn't a great rush of german ,dutch ,Belgian or French drivers rushing to work over here because they were no cheaper than us. It wasn't until the EU was expanded into former soviet block countries that the wave of cheap foreign drivers arrived in this country , and businesses realised they could hire these drivers for a lot less than they were paying us. That's as much the reason for the driver shortage as brexit.
Also foreign trucks don't have to go back empty, nor do we.
I'm not sure if cabotage is back in operation or not.
- UK and EU road hauliers will be limited to a maximum of two journeys within the other’s territory before having to return to their own territory.
- UK operators will only be permitted to undertake one extra operation within the same member state, called cabotage, meaning the second would have to take them to another EU member state.
I suppose it depends on who's keeping an eye on them, i'm sure there will be chancers out there.