WASHINGTON — The future of trucking may tell us a lot about the future of work. It’s no secret that many Americans fear losing their jobs to automation. In a Pew Research Center poll last October, nearly three-quarters of respondents worried that “computers and robots could do most of the work currently done by humans.” And yet the job market seems to be sending the opposite message: With a low unemployment rate of 4.1 percent, many companies say they can’t find good workers.

Trucking symbolizes the contradiction. Trucking companies complain they can’t hire enough drivers, and the situation will get worse before it gets better. Why? The nation’s 3.5 million truck drivers are aging. More than half (55 percent) are 45 and over, and only a quarter are younger than 35.

Not to worry, experts say: Trucks can be automated into driverless vehicles. Presto, the shortage vanishes. But this creates its own problems, more for society than for the trucking industry. Yet another source of jobs for blue-collar workers, mainly men, withers. This bodes ill for economic equality and family stability, as men have a harder time finding well-paying jobs.

Not surprisingly, truck drivers are often cited as an example of impending job destruction wrought by automation. But the reality is more complicated. A new study by Uber argues that millions of driver jobs will survive well into the future and that the spread of driverless trucks may actually stimulate the need for more — not fewer — drivers.

The explanation lies in the plausible limits of driverless technologies. Here’s what the Uber study says:

“The biggest technical hurdles for self-driving trucks are driving on tight and crowded city streets, backing into complex loading docks and navigating through busy facilities. … These maneuvers require skills that will be hard for self-driving trucks to match for a long time.”

Based on this view, Uber argues that the trucking industry will split into two parts. Long-haul transportation over major highways will be performed increasingly by driverless tractor-trailers that will deliver freight to “transfer hubs” on the edges of major cities. There, local workers and drivers will reload the cargoes and make delivery to final customers.

This system, Uber argues, will be more efficient for shippers and more attractive to drivers. The study assumes that “each self-driving truck could do the work of two of today’s trucks because they can operate at all hours of day and night.” Now, trucks spend only about a third of their time on the road. By doubling this, self-driving trucks would cut costs. Lower costs in turn would stimulate more shipping. Combined with normal growth, this would require more drivers, despite the increase in driverless trucks.

Meanwhile, many drivers might prefer local employment. “Driving a truck is a tough job,” says the report. “The hours can be long and grueling. … In some cases, trucking can keep drivers away from home for up to 200 nights a year.”

Of course, we ought to take all this with some skepticism. Uber hopes to make a business of long-distance driverless freight transportation. Its intriguing analysis is not entirely disinterested. Presumably, it wants to defuse opposition to driverless trucks.

Still, the study makes a broader point: Automation — meaning almost any technology that promotes efficiency — has been eliminating jobs for decades without crippling the economy’s ability to create new jobs. Recent examples include: kiosks in supermarkets and drug stores; automated parking lots and garages; automated teller machines. Although jobs were lost, others have taken their place.

Economist Timothy Taylor, who posted the Uber study on his useful blog (“Conversable Economist”), puts it this way: “A simple ‘technology replaces jobs’ story … is always more complex and sometimes even counterintuitive to how it may appear at first.”

Robert Samuelson is a columnist with The Washington Post.

Robert Samuelson