As Adam “MCA” Yauch’s bass line fuzzed through the speakers, and the crowd—encouraged by Tesla Motors (tsla) CEO Elon Musk to “jump over the barriers”—flooded the airplane hangar just outside Los Angeles, there was talk of an impending revolution. It certainly felt that way to onlookers. Excited energy crackled in the crisp California air.
In truth, the revolution—or evolution, depending on who is talking—was already underway. But that didn’t stop Musk from making his grand entrance in the sleek Tesla Semi, an all-electric heavy-duty truck that could well disrupt the commercial trucking industry.
Dozens of companies, from truckmakers like Daimler and Navistar to startups like Chanje and Embark—plus Uber’s Otto and Waymo, the erstwhile Google self-driving project—are pursuing what they believe is the next generation of trucking. Their vision includes electric powertrains, autonomous driving technology, and oodles of wireless connectivity—a vision now shared, naturally, by Tesla and Musk.
There are good reasons why so many companies are suddenly fixated on modernizing a century-old industry. Stricter carbon emission regulations play a part. The swift rise of e-commerce does too. And technological breakthroughs, particularly around autonomous driving, are advancing far beyond the proving ground.
But above all, it’s business opportunity—and trucking is the physical embodiment of a thriving economy. Trucks moved more than 70% of all U.S. freight and generated $676 billion in revenue in 2016, according to the American Trucking Associations. Some 33.8 million trucks were registered for business purposes in 2016. Almost 4 million of them were categorized Class 8, denoting the largest freight trucks.
Without the trucking industry, the economy would screech to a standstill. So it stands to reason that anyone who can make it more efficient can collect profits from coast to coast.
Technology leads the way. The newest trucks on the road, such as those made by Volvo and Freightliner, employ driver assistance technologies similar to the adaptive cruise control and lane-keeping features found in modern passenger cars. The technologies make driving a truck less stressful, safer, and more fuel efficient. Autonomy promises further improvement.
Starsky Robotics CEO and cofounder Stefan Seltz-Axmacher believes trucking is on the verge of radical change that hasn’t been seen since the industry was deregulated in 1980. “Billions of dollars were lost and made,” he says. “Autonomous trucks are going to be an even bigger change than that.”
Seltz-Axmacher’s company, which is based in San Francisco, uses software, radar, and computer vision cameras to enable long-haul trucks to drive by themselves on the highway, then cede control to a remote operator to travel from exit to final destination. In September, a Starsky Robotics truck drove 68 miles on a Florida highway with zero intervention by a human.
Other autonomous trucking startups are in hot pursuit. TuSimple, a company that has operations in China and San Diego and is backed by Nvidia (nvda) and Sina Corp., plans to test fleets on two routes: one 120-mile stretch between Tucson and Phoenix and another segment in Shanghai. Meanwhile Nikola Motor is designing and building its own driverless, hydrogen fuel cell–powered Class 8 truck—“the iPhone of trucking,” says CEO Trevor Milton. “In the next eight years, you’re going to see a complete transformation of trucking,” he adds.
So where does that leave a company like Daimler, whose first truck arrived to market in 1896? In embrace of the long view. Daimler, which sells more than 400,000 trucks globally each year, is treading carefully as it brings technology to its commercial vehicles. “It’s definitely an evolution,” says company spokesman Florian Martens. Not, he hints, a revolution.
Tesla insists otherwise. Its $180,000 Semi promises up to 500 miles on a single charge—four times the range of an electric truck that Daimler is developing. Customers like Walmart (wmt) and Meijer have made reservations for a Tesla Semi prototype expected in 2019, but skeptics remain. “These orders are for publicity and the halo effect of seeing a quiet, clean electric truck and not a black-smoke-belching diesel engine,” says Darren Gosbee, vice president of engineering for Navistar. (Tesla declined to comment.)
In other words, the trucking industry tends to embrace technology slowly. It took time to adopt electric propulsion and autonomy, Gosbee says. “Connectivity has proven to be the only exception,” he says. “And that’s because the benefits have been so revolutionary that the customers can’t get enough of it.”
Perhaps that’s what Musk is betting on.
A version of this article appears in the Dec. 15, 2017 issue of Fortune with the headline “The Next (R)evolution.”