Humans need to choose job families that will exist their entire working life (40-50 years). Even if the technology takes 30 years to develop, drivers will be 50 years old and forced into early retirement due to.
I suspect that driver shortages will get worse before they get better, b/c if we are "25 years out" from self driving long haul trucks, ppl will shy away from that job category so they don't get caught jobless before they are ready to retire.