It’s a bit intimidating, strolling with the crowd that drifts along this narrow lane. The space is actually a parking lot, asphalt marked out with long yellow strips. What gives it the feeling of a narrow road is the sheer vertical reach of the structures parked on either side: rows of tricked-out big rigs, their gleaming grills and faces towering over the avid passersby, almost mocking the scale of the walking being with the little chrome flying pigs and cigar-chomping ducks mounted so impudently on their hoods.

The trucks tonight have come alive. Banks of LEDs pulse in flashes of red, blue, orange, and green, shimmering in the glitter scattered under the wheels. Engines thrum and rattle from all sides. One truck sends out tongues of propane flame from its ten-foot stacks. The smells of diesel fumes and cigarette smoke are heavy in the air. There is something menacing and almost infernal about these giant machines. And indeed, one of the trucks that seems to have the most magnetic appeal here at the Super Truck Beauty Contest in Walcott, Iowa bears rings of wicked spikes on each of its rims and piping that glows in green like bones, facing the world with a small army of leering metal skulls. LAWLESS, says the back of the matte black cab. Nothing more than a ditch and a chain-link fence divides us from the traffic roaring along I-80.

The massive sign looming 139 feet overhead explains where we are: Iowa 80, the “World’s Largest Truckstop.” A thousand trucks and four thousand cars pull in each day at this stop along the interstate, a few miles west of the Mississippi River and the Illinois border. For nearly four decades, the truck stop has sponsored an annual Truckers Jamboree, drawing thousands of truckers, truck enthusiasts, and curious onlookers to its sprawling grounds. The crowds are a mix of families running after children and taciturn older men. Magnets for sale in the gift shop trumpet proudly defiant declarations: “I like truck fumes” or “Nobody governs my truck.”

Many of the show trucks on display at the Iowa Truckers Jamboree celebrate the American flag and the Armed Forces on the one hand, but a kind of outlaw or renegade culture on the other. The rise of this outlaw culture in American trucking coincided with the emergence of new regulations on maximum speed and fuel efficiency in the 1970s. In the face of such developments, love of diesel and its signature black fumes emerged as an assertion of individual sovereignty and freedom.

Blasting clouds of black smoke, or “rolling coal,” has long been a way of conveying disdain in American trucking culture. In the last decade or so, such coal rolling has gained notoriety as a carbon-loving practice, with countless YouTube videos showing hapless bikers and walkers blanketed in thick clouds of smoke emitted from the stacks of diesel trucks retrofitted to deliberately flood their engines with excess fuel.

In June 2018, Colorado became one of the first states to ban such “nuisance exhibition of motor vehicle exhaust” on roadways. “We get a few reports each weekend night,” David Kaes, a patrol officer with the Fort Collins Police Department told me one afternoon this summer. Kids in high school or just past that age would come into the city from the surrounding countryside on weekends, cruising College Avenue in modified trucks. Kaes was a diesel enthusiast himself, and when he wasn’t charged with pulling them over, he struck up conversations about what the kids had put under the hoods of their trucks. “Yeah, we smoked ’em out,” they’d tell him slyly, recalling an encounter with some “pansy Prius driver.”

Going home after duty one afternoon, Kaes pulled up at an intersection behind a little smart car and a diesel Dodge with a raised chassis. He watched as a guy leaned out of the passenger window of the Dodge and called down to the driver of the smart car. “What’s it wanna be when it grows up?” he asked with a sneering laugh, the truck enveloping the car in a cloud of black fumes when the light changed and the Dodge sped off. Like many, Kaes saw coal rolling as a matter of masculinity and defiance, thumbing the perpetrator’s nose at a state that threatened to go after their trucks and guns. “This is America. You’re not gonna tell me what to do with my truck.”

I was in Colorado for the Five-R Trucks and Trailers Truck Fest at the Bandimere Speedway in Morrison, west of Denver. The flyer promised plenty of black and ominous smoke, which came in loud and regular bursts from the racetrack over the course of the day. I figured that people here would be angry about the new law, but everyone seemed so earnest and law-abiding when I asked about coal rolling. “We’re not assholes,” a welder with two Tea Party stickers on the back of his 2005 Dodge told me. “People don’t understand that about us. Come after my guns, and I will do what I can to hang on to ’em. But we need laws. You have to keep people safe. This is a civilization. If everyone just did whatever they wanted, there’d be chaos.”

It took me a long time to find someone willing to admit that they’d deliberately rolled coal deliberately onto someone else, themselves. The founder of a local truck club called over a friend, Michael, a guy in his twenties who delivered pool tables for a living. He smiled when I asked whether he’d ever smoked anyone on purpose. “Only if they’re tailgating me, or if they cut me off,” he said. “If they keep their distance, it’s OK. Some of these drivers, even people on bicycles, they don’t always follow the rules they’re supposed to follow.”

Michael drove a black 2005 F350, a pair of exhaust stacks mounted to the bed in the back. “It was my dream truck,” he told me. He couldn’t race it because it leaked too much fluid; they wouldn’t allow it onto the track. But he’d put in all of the work on it himself, and this was the truck that he used each day to haul tables from place to place. He’d trained to be a diesel mechanic. He insisted that diesels were cleaner than gasoline cars. The smoke itself was soot; it would fall to the ground. He wasn’t ashamed to admit that he smoked a driver every now and then, and the new law wouldn't change how he drove or what he did. For him, it came down to the aggression shown by other drivers, not his own. “It’s a way of saying: hey, give me some space.”

“Let me ask you something,” I responded. “Say you had your window down, they had their window down. Couldn’t you just shout at them and say something like, ‘Hey asshole, why’d you cut me off?’” Michael laughed and shook his head. “Then you get into things like road rage. You don’t know if they’re carrying a gun. That isn’t something I’d want to do.” Better, it seemed, to make your point and speed off quickly before they managed to react.

What, then, is the horror that lives on American roads? The monsters are not the trucks themselves or the people that drive them, although there is a great deal of pleasure to be had in playing at this idea. The true monstrosity of our road culture lies in the way that we navigate the world in speeding bubbles, isolated and sealed off by hulking walls of steel as well as the fuel that propels them. There is a kind of talk that happens in noise and smoke and the words lettered onto the odd bumper sticker, but the pace of things is such that there’s scarcely an occasion for dialogue. I think of the truck hurtling down the Bandimere Speedway that day, not one flag but three fluttering from its bed: an American flag, a Confederate flag, and then yet another Confederate flag with an assault rifle planted at its center. “Come and take it,” the words at the bottom of this third flag screamed, knowing full well that at that speed, such a response would be impossible.