From behind the wheel of his big rig, Eric Feehan can’t quite envision a future when 18-wheelers drive themselves.

“There are so many variables, I don’t think anybody’s going to make it work,” the Minnesota truck driver said during a break in Sparks, Nev.

In 24 years on the road, Feehan has learned that it takes experience and instinct to react when your truck is buffeted by 40 mph winds, to sense the moment when wet highways turn to ice, or to anticipate when a car is going to swerve in front of you.

“There’s no way they’re ever going to program that into a self-driving truck,” said Feehan, who lives in Farmington and regularly drives to Arizona and California.

They’re working on it, though. While advancements in autonomous — or self-driving — cars get much of the attention, development of self-driving commercial vehicles is speeding forward. Complex questions involving safety, security, liability, regulations and infrastructure remain, making widespread use years away, but trucks that operate with minimal driver involvement are being tested now. Tesla will unveil an electric autonomous semi on Oct. 26, and most major truck makers are working on versions.

The Trump administration is encouraging progress with what it calls a “nonregulatory approach” to autonomous vehicles, which means that it wants as few rules as possible. That has exacerbated some safety concerns.

“When we’re talking about vehicles … the size of a house going 70 miles per hour down our freeways,” said Jason Levine of the nonprofit Center for Auto Safety in Washington, “there’s a real concern that the technology isn’t ready yet to be released into the wild.”

In the early stages, experts say, some kind of technician or operator would still be in the cab. But the end goal is a truck that could drive itself.

Proponents note that 94 percent of traffic deaths are caused by human error. In theory, there would be fewer as self-driving vehicles multiply.

“This technology is not just coming; it’s here,” said John Hausladen, president of the Minnesota Trucking Association, which has a task force on autonomous vehicles that met for the first time in September.

Gary Pressley, a task force member and president of Heavy Metal Truck Training in Eagan, said that activity is picking up. Last month, the issue was among topics he discussed at a retreat held by a trucking company in Green Bay, Wis., and at a national meeting of the Commercial Vehicle Training Association in San Antonio.

“We’re talking years and years of testing and acceptance” before autonomous trucks become commonplace on America’s roads, Pressley said. “It’s not going to be next year. … But it is coming.”

The state is preparing. Ray Starr, assistant traffic engineer at the Minnesota Department of Transportation, is on a self-driving vehicle committee with other state agencies — including Public Safety, Commerce, the State Patrol and the Council on Disability — that meets quarterly. Autonomous vehicles are on the agenda for the Oct. 26-27 meeting of the state Toward Zero Deaths initiative, which focuses on reducing traffic fatalities.

The state will soon test an autonomous bus. “Vehicles are changing very quickly,” Starr said, and the state must factor that into its 20-year transportation plans, which “quite likely will change drastically.”

Congress and the Trump administration are taking steps to keep up with the future of transportation:

• On Sept. 6, the U.S. House passed a bill that didn’t deal with trucks, but would loosen regulations for autonomous cars, allowing companies to test up to 100,000 of them on regular roads, even if they don’t meet federal safety standards. It also would prevent states from banning self-driving cars.

• On Sept. 12, Transportation Secretary Elaine Chao released guidelines that advise makers of self-driving cars that they can submit safety assessments to the National Highway Traffic Safety Administration, but they aren’t mandatory.

Levine disapproves of the administration’s hands-off approach to managing the burgeoning industry. “The regulatory structure exists to create the guardrails for safety,” he said. “Unfortunately, we’re not seeing an administration that wants to take the lead on this.”

But Eric Paul Dennis, a research analyst at the nonprofit Center for Automotive Research in Ann Arbor, Mich., said that growth should come before rules. “I can’t think of another example where there has been such an attempt to regulate something that doesn’t exist,” he said.

• On Sept. 13, the U.S. Senate Commerce, Science and Transportation Committee debated whether trucks should be included in its bill encouraging innovation by allowing exemptions from some federal regulations.

Sen. Gary Peters, D-Mich., said that he had “serious concerns with including self-driving trucks” until there’s “a much more robust discussion and evaluation of the impact.”

Chairman Sen. John Thune, R-S.D., said, “It doesn’t make sense to have two safety standards out there — one for trucks and one for cars.”

The committee approved the bill on Wednesday. It excludes commercial trucks from provisions that would allow more autonomous cars on roads, but includes light trucks — a class that includes vans, pickups and SUVs. A vote in the full Senate has not been scheduled.

At the hearing, Ken Hall of the International Brotherhood of Teamsters told senators not to forget “the potential impact on the livelihoods and wages of millions of your constituents.” Jobs, he said, should be considered “at the outset of this discussion, not after the fact.”

Investment company Goldman Sachs projected in May that autonomous cars could replace 6.2 million professional drivers by 2030. The trucking industry is experiencing a national driver shortage.

Hausladen said that autonomous trucks could alleviate the shortfall, but added, “Critical driver functions aren’t going away.” Pressley said that as technology evolves, so will operators’ roles. “The next phase might be that the driver becomes a technician,” he said. That could attract young, tech-savvy drivers, but also would require advanced training.

“If we come forward with the [autonomous truck] technology, I suspect it’s also going to drag along new jobs,” said state Sen. Scott Newman, R-Hutchinson, who chairs the Senate Transportation Finance and Policy Committee.

Newman would like to hold an informational hearing on the evolving technology.

Adam Thierer is a senior research fellow at the Mercatus Center at Virginia’s George Mason University, which links academic research to public policy problems. He believes that we’re witnessing not just an industrial transformation, but what he called a “pacing problem: the problem of technological innovation outstripping the ability of regulators to keep up.”

The current discussion about autonomous vehicles “foreshadows upcoming debates about other robotic systems,” Thierer said. “The bottom line is the necessity of more flexible approaches by federal and state regulators for emerging technologies.”

So what’s next? Norway plans to launch the first crewless, autonomously operated cargo ship later this year.