At first glance, the 18-wheeler, white with green lettering crawling down its side, looked like any other heavy-duty truck on the road.

The vehicle merged onto the busy Florida Turnpike earlier this month, smoothly changing lanes and reaching 55 mph before eventually exiting the highway nearly 10 miles later.

The truck didn’t have any cargo, but it was carrying a closely guarded secret: There was nobody in the cab.

Owned by a start-up called Starsky Robotics, the vehicle is the latest example of self-driving trucks being tested on public roadways and follows similar tests across the nation by companies such as Uber, Waymo, Tesla and Volvo, usually with a human backup driver behind the wheel.

Unlike most of the trucks being developed by those big-name companies, Starsky Robotics’s trucks aren’t fully autonomous — they are simply unmanned. That means the vehicles use a hybrid driving system in which computers make some driving decisions, but a remote human operator sitting in a faraway control room surrounded by screens and a steering wheel makes others, particularly during challenging stretches of road.

The company’s goal is to create a “driverless” freight company that stretches across the Southeastern United States.

Starsky Robotics’s 29-year-old co-founder and CEO, Stefan Seltz-Axmacher, believes his scrappy, 30-person company has a built-in advantage. Unlike his competitors, he said, his company is not beholden to the dogma of building a technically pure general-autonomy system.

“When it comes to driving a truck, a decent person paired with a decent artificial intelligence is better than the best person or the best AI,” explained Seltz-Axmacher, saying that — for all our concerns about intelligent machines — engineers are a long way from developing AI that can replicate people’s fluid intelligence. “The tech industry doesn’t give humans enough credit, but they are really good at a lot of things that computers don’t do very well. Even mimicking the intelligence of an animal is really hard, let alone a person.”

In this case, he added, humans are better at navigating off ramps and lane changes, but machines are better at maintaining focus during long, unimpeded stretches of roadway.

Seltz-Axmacher thinks his company offers a potential solution for an industry that has experienced a nationwide shortage of employees for more than a decade, a deficit that has led to a sharp increase in shipping costs in recent years.

As The Washington Post’s Heather Long reported last year, the shortage is being exacerbated by several factors: low unemployment, a humming economy that has created heavy demand for trucks, and younger workers steering clear of jobs they believe will be phased out by automation.

The Bureau of Labor Statistics estimates the average age of a commercial truck driver in the United States is 55, with more than 90 percent of them male.

The truck driver shortage stood at roughly 36,500 in 2016 but was expected to surpass 50,000 by the end of 2017, according to most recent figures from the American Trucking Associations.

“Demographics are working against the industry,” Derek Leathers, CEO of Omaha-based trucking company Werner Enterprises, told NPR last year. “The trucking industry average age is about 10 years older than the average age across other comparable industries like manufacturing and construction. So as those retirements are taking place, we’re just not seeing the same level of new entrants into the industry.”

For a middle-aged truck driver supporting a family, the benefit of remotely operating a truck is obvious, according to Seltz-Axmacher: getting to leave work at the end of the day and go home and see your loved ones. The CEO says he has met truckers who have interacted with their children for only a few days a month for more than a decade.

“Driving is difficult, and it’s a hard job,” he said, noting the long hours and isolation. “But what makes it even harder is how it impacts people’s personal lives.

“I don’t know many truck drivers who have been on road for at least 10 years and don’t have a complicated family situation.”

Removing drivers from trucks will also allow the industry to remodel the vehicle’s cabins, which are designed for comfort to entice and retain drivers, but make trucks less fuel efficient, raising shipping costs, Seltz-Axmacher said.

Starsky Robotics has no shortage of competition in the trucking space. Beginning last year in nearby Georgia, Waymo — formerly known as Google’s self-driving car project — unveiled a pilot program in Atlanta using Peterbilt Class 8 trucks to carry cargo bound for Google’s data centers.

Tesla is also developing a long haul semitrailer truck that would include semiautonomous features for highway driving.

Last year Uber announced that the ride-hailing giant was shuttering its self-driving truck program, a division that made history in 2016 by completing the world’s first autonomous truck delivery — 50,000 cans of Budweiser.

More reading: