Driverless technologies are disrupting transportation around the globe. Though most experts disagree on when humans will be replaced behind the steering wheel by artificial intelligence, few doubt that it will happen.

Until now, passenger cars have taken center stage in the transformation from driven-to-driverless. It makes perfect sense; people movers are currently at the heart of the "Mobility as a Service" business model popular within the transportation sector and taking the human driver out of a bus, cab, ride-share, whatever form of mobility service it might be, is the quickest path to profitability.

But the more the industry experiments within MaaS, the more it feels that the car's 18-wheeled counterpart—like the tractor-trailer or long-haul truck—will make the most immediate socio-economic impact. It's a matter of the early bird gets the worm, as the saying goes.

Technically, speaking

Cars and trucks are taking very similar roads to autonomy. They use comparable sensors (ultrasonic, radar, lidar, cameras, and so on)—albeit trucks use more of them—and both are using a step-approach to autonomy, as truck-makers are starting to offer a wide array of advanced driver-assist systems like emergency braking, blind spot monitoring, adaptive cruise control, lane keeping, traffic jam assist, and more.

However, trucks aren't merely longer, heavier cars. So, when it comes to programming, the technological obstacles facing those writing code to match the situational awareness of a professional truck driver—skills honed by years of experience and training—are higher than, say, replicating your everyday commuter, especially in urban environments.

"Cities are harder for trucks," explains Jim Scheinman, a venture capitalist at Maven Ventures who specializes in backing autonomous technology start-ups like Cruise and Embark. "[There are] confusing road signs, questionable rights of way, pedestrians, narrow streets with multiple points of entry, etc." So navigating a big rig in a city can be a hazard for even the most seasoned driver, let alone an untested robot.

Fortunately, big rigs don't need to self-drive in a city and may never need to. "Long-haul trucks spend most of their time on the open road where the driver doesn't have to account for pedestrians, cyclists, traffic lights, or other complex variables," says Scheinman. "It just has to stay within its lane and keep a safe distance from fellow travelers. Consequently, it's easier to program a system that can drive itself on the highway than in an urban or even suburban environment—much easier."

In fact, Scheinman says the functionality is already here. "I recently participated in a [semi-autonomous] truck demo on US-101 in Northern California. The driver did nothing for more than an hour. The truck simply drove itself." However, he admits the ability to self-drive on the highway is about two years away from being commercially available.

Before continuing, it's important to note that there are no fully autonomous vehicles—those that can go anywhere, anytime, under any conditions—on the road today, nor will there be for many years. There are plenty of vehicles equipped with varying levels of driver assist technologies, though. The kind of driver-assist features a vehicle has affects where it ranks on the Society of Automotive Engineers' bewildering autonomy scale, which ranges from "Level 0" no automation (where a fully engaged driver is required at all times, with no traction control or even ABS) to "Level 5" full autonomy (where an automated vehicle operates independently, without a human driver).

There's a lot of money to be made

Self-driving trucks share the same anticipated benefits of self-driving cars—improved safety, better fuel efficiency, lower carbon footprint. Plus, they also have a tremendous influence on the US economy and workforce.

According to the US Census Bureau, there are approximately 15 million trucks currently in operation across the country, of which 2 million are tractor trailers or long-haul trucks. To keep those big rigs on the road, the industry employs approximately 1.7 million drivers. More importantly, they transport 70.1 percent of all domestic freight, which earned the trucking industry more than $726 billion in 2015. That's more than the sales of Google, Amazon, and Walmart combined.

By taking the driver out of the equation, even part of the time as suggested by Scheinman, financial analysts at Morgan Stanley estimate the industry could've banked another $168 billion: that's $70 billion from reducing staff (drivers are associated with 34 percent of operational costs per mile), $35 billion from improved fuel efficiency, $27 billion from better productivity, and $36 billion from repairs and litigation based on driver-related incidents.

Over the next decade, the amount of freight moved by long-haul trucks is expected to increase by 27 percent. So, a lot more money is to be made. Unfortunately, there most likely won't be enough drivers to supply the demand. The trucking industry is finding it increasingly difficult to hire, train, and retain long-haul drivers, a problem that has been plaguing the industry since 2005. Autonomous technologies seem to be the answer to an industry struggling to meet demand.

What will happen to drivers?

Self-driving trucks do pose a potentially serious threat to employment as long-haul trucker remains one of the country's most common professions in the US.

However, most believe that automated technology is unlikely to replace truckers anytime soon—it will, however, alter the nature of the job. "We're not trying to get rid of drivers," says trucking executive Robert Haag, vice president of operations for Perfect Transportation. "We're trying to enhance the safety, allow drivers to be more productive, create a better return for the company, and supply a better service for our customers. Drivers will be less involved with physically driving the truck, and more with monitoring the truck and establishing and maintain customer relationships." They are likely to become the highway equivalent of an airline pilot.

It is still a very divisive topic, though. Self-driving developers are broadly split into two camps: those working on interim solutions in which a human driver is assisted by self-driving technologies as we discussed; and those who are focused on removing the human from the vehicle as soon as possible like tech start-up Starsky is aiming to do.

TuSimple, a Chinese startup building autonomous truck technology, is also on a mission to rid trucks of drivers all over the world. Like Starsky, getting rid of the driver is key to its plan, Xiaodi Hou, TuSimple's co-founder and chief technology officer, told Trucks.com. "Otherwise, the savings that fleet managers would achieve by making the switch to autonomous trucks would not be significant enough to warrant the investment if the driver is still a factor."

In addition, new jobs will emerge as a result. This is not the first time we've had job transition as the result of technology evolution. "All of the studies show that after technology breakthroughs usually more jobs are created," says Scheinman. But the jobs will be technical in nature. "Sensors, navigation systems to drive on the road. They brake independently and use radars and cameras to navigate around other vehicles. They will still need people in the trucks who can maintain these systems. It will be less involved with physically driving the truck, and more with monitoring the truck," says Haag.

So, what will future shipping look like?

The landscape probably won't transform dramatically over the next few years, says Raj Rajkumar, IEEE Fellow and Professor of Electrical and Computer Engineering at Carnegie Mellon University. "The first step will be to establish autonomous driving from exit-to-exit." A driver pilots the truck onto the highway engages the driving system then takes a backseat. As the truck gets close to the destination, the driver takes back control of the "last mile." So, a human will deal with the complexities of urban and suburban contexts, piloting the vehicle through constrained roadways and loading docks.

This will conceptually allow the vehicle to stay on the road longer. "Trucks are only profitable if they are moving and on time," says Mike Cammisa, vice president of safety, policy, connectivity, and technology for the American Truckers Association. "No driver, no mandatory stops." By law, drivers are restricted to 11 hours of driving a day. They must pull-over and rest for at least 8 hours between shifts and at least 34 hours after a 60-hour week.

"But over the next 20 years, as self-driving technology develops, the process will evolve to include last-mile delivery services," says Rajkumar. "[It will be] taking freight from Point A to B with no human involvement. In that scenario, trucks could ride from manufacturer right through to buyers. Drivers do nothing but customer service."

Trucks can also be used as rolling fulfillment centers: a possible scenario could involve a consumer ordering something online, and that retailer already has the product on a truck in the vicinity. That truck would simply stop at a strategic exit near the consumer and unload it to a smaller autonomous truck or a drone for final delivery. No more big rigs blocking traffic while trying to navigate narrow city streets.