On Thursday night, Elon Musk rolled out Tesla's biggest gizmo yet: a fully electric semitruck. The Semi can go a whopping 500 miles between charges, hauling 80,000 pounds along the way. And it can sorta, kinda drive itself—on highways, anyway. The truck comes with Enhanced Autopilot, the second generation of Tesla's semiautonomous technology, equipped with automatic braking, lane keeping, and lane departure warnings.

"Every truck we sell has Autopilot as standard," Musk said of the Semi, which goes into production in 2019. "This is a massive increase in safety."

That may be true—about 4,000 Americans die in truck-related collisions every year, and human error is responsible for many of them. Self-driving trucks will certainly change lives. That goes double for the nearly 3.2 million people currently employed as delivery and heavy truck drivers. But we don't know how: A dearth of research means that no one really knows what effect automation will have on the sector. It's clear that truck driving will change, though, and companies testing autonomous trucking today in Florida and California and elsewhere show what that new future might look like.

Driving Today

Trucking jobs are, as a recent report from the Washington, DC, think tank Global Policy Solutions points out, solid, middle class jobs. The median annual wage for delivery and heavy truck drivers is $34,768, 11 percent higher than the country's median wage. Trucking has also been an opportunity for black, Hispanic, and Native American workers, who have faced serious, race-based barriers to entry in other blue collar jobs and are now overrepresented in the industry. Many trucking jobs are unionized, and the gig doesn’t require an advanced education. You probably won't get rich doing it, but driving a truck is an option for those—men, in many cases—who might otherwise have done the kind of factory work that's left the country in the last three decades or so. Losing these jobs outright could devastate them.

Truck driving is, at the same time, a not-so-great job. Driving is solitary, physically inert, and psychologically exhausting. And long-haul truckers can be on the road—and away from family and friends—for months at a time. So people leave. In fact, there aren't enough truck drivers to go around. The American Trucking Associations reports the annual driver turnover for large truckload carriers reached a whopping 90 percent this year, and it projects a 50,000-driver shortage by the end of 2017.

Meanwhile, the freight shipping industry grows like Elon Musk's plans for the future. Today, trucks carry 70 percent of all goods shipped in the US, about 10.7 billion tons this year, pulling in $719 billion in revenue. And thanks to a burgeoning economy and population, ATA expects the industry to swell by 3.4 percent annually until 2023. Robo-trucking could help the sector dodge growing pains.

And, better, autonomous driving on highways should be easier to figure out than driving in cities, because those big rigs don't need to navigate pedestrians, cyclists, and traffic lights. That means most of the country's first experiences with driverless vehicles may be in the form of 70,000-pound trucks, instead of the kinds of driverless taxi services testing in sections of Pittsburgh and Arizona.

Driving Tomorrow

But what does the future look like for truck drivers? That kind of depends on how you define trucking. Because autonomous big rigs aren't going to be 100 percent autonomous, at least not in the near or medium future.

For example: Peloton Technology, a 6-year-old startup, envisions “platooning” trucks that can travel in packs and “talk” to each other via radio waves. Drivers in these trucks need only sit at the wheel if their vehicle leads the platoon; others can fill out paperwork, nap, or sit at a laptop and manage the fleet’s logistics network (though they'll probably need more training for that). Autonomous startup Embark sees a future in which drivers are more like tug boat pilots, waiting at a highway’s exit ramp for self-driving trucks to arrive and driving them into “port”—in this case, a distribution center. (The company announced this week it’s using semiautonomous vehicles to ship refrigerators between Texas and California, though today there’s always a safety driver inside to monitor the tech.)