From stories I have been told over the years I have learned back in the 1970s truck drivers were simply asked can you drive a tractor trailer? If they answered yes they were told to go to the DMV to get their picture taken. They were also part time mechanics and if they got stranded on the road they had to be ready to fix the issue and get back on the road. They carried a bucket with items like work gloves, flashlights, a battery-operated radio, maps, light bulbs and various tools. Today is different. Much more oversite and requirements on their license and skillset. But today's drivers only tools may be a bottle of water, a cell phone, and a charger.