Many motorists cruising highways recently have likely found themselves stuck behind a truck that seems to be moving more slowly than usual. That perception is real. With diesel prices rising, truckers are dialing it back, trading speed for fuel economy, and in the process, subtly shifting the cadence of global supply chains. “In the United States, trucks carry more than 70% of all freight,” says Penn sociologist Steve Viscelli, who studies the economics of trucking. “So, when diesel spikes, transportation costs rise, supply chains tighten, and everyday goods—from fresh produce to consumer electronics—become more expensive. But fuel is only part of the story.” Viscelli talked to Penn Today about some of the challenges facing American truckers today. How does a spike in diesel prices reach consumers? Diesel’s incredible energy density makes it the lifeblood of logistics. A typical big rig weighs 40,000 pounds unladen, and legally, you can load an additional 40,000 pounds of freight on top of that. To move an 80,000-pound vehicle across the country, diesel is currently the only real way to do it. When you look at energy-intensive, long-haul operations, diesel can make up over a third of your total costs. When diesel prices spike by 20% or 25%, the effects cascade instantly. When those costs spike, logistics can account for approximately 8.8% of our GDP. A sustained spike has the potential to create a percent or two of inflationary pressure across thousands of categories of everyday items we all need. How has the trucking job market changed in recent years? It goes back to deregulation. We used to regulate trucking almost like a public utility to ensure a level playing field. Prices were collectively set, and the government made sure rural places didn’t get gouged by carriers. Before the 1980s, trucking was a really good