Imagine being a cyclist, pedaling to work, when suddenly a passing semi-truck nearly knocks you off your bike—twice. But instead of cursing the driver, you’re hit with a stroke of genius. That’s exactly what happened to Edwin J. Saltzman, a NASA aerospace engineer, back in 1973. While biking to NASA’s Dryden Flight Research Center (now the Neil A. Armstrong Flight Research Center), he noticed how the aerodynamic wake of semi-trucks first pushed him toward the road’s shoulder and then pulled him back—a terrifying experience for most, but a Eureka! moment for Saltzman. And this is the part most people miss: that accidental discovery would spark a revolution in semi-truck aerodynamics, saving millions in fuel costs and reshaping the trucking industry.
As detailed in a recent post by the American Truck Historical Society (https://www.facebook.com/ATHSHeadquarters/posts/pfbid02gxvYN9gKDZ77jxQvE2FgwtVygPDRzSYaXghyfmQJLyk5EFFdtzqFfMXYtT6qczHvl), Saltzman realized that trucks were essentially fighting the air, creating drag that wasted fuel. He wondered: What if we could help them slice through the air instead? With a team of colleagues and an old Ford van from the Dryden motor pool—transformed into a bizarre-looking test vehicle—Saltzman set out to answer that question.
Here’s where it gets technical but fascinating: the team started by covering the van in flat aluminum sheets with sharp 90-degree corners. This wasn’t just for looks—it created a baseline to measure drag, mimicking the boxy design of motorhomes at the time. Then, they systematically rounded off edges, starting with the front vertical corners, followed by other surfaces, and finally sealing the vehicle’s underside. Each change smoothed the airflow, reducing drag significantly. For context, a typical truck’s broad front end plowed through the air, creating uneven flow and low-pressure zones at the back—all major sources of drag.
The results were staggering. Rounding the front edges alone reduced drag by 52%, while sealing the underside added another 7% reduction. Translated to fuel savings? A whopping 15-25% improvement at highway speeds. But here’s where it gets controversial: Does focusing on aerodynamics distract from other critical efficiency factors, like engine design or tire technology? Saltzman’s team didn’t stop at the van. They later applied similar modifications to a leased semi-truck, smoothing its blunt front end and adding a fairing over the cab. The outcome? Another 50% drag reduction, with underbody fairings and a boat tail contributing an additional 15%.
Sure, the test truck looked crude—almost comically so. But is it any stranger than the designs emerging from the Energy Department’s SuperTruck program? Manufacturers like Navistar (https://www.thedrive.com/news/new-international-supertruck-ii-prototype-semi-gets-an-impressive-16-mpg) and Kenworth (https://www.thedrive.com/news/kenworths-wild-supertruck-2-concept-semi-doubles-efficiency-with-bullet-train-aero) are now pushing boundaries with futuristic rigs. And NASA’s research hasn’t just collected dust—it’s directly influenced modern truck design. Today, aerodynamic fairings, rounded corners, and even vortex generators (like those marketed under the Airtab brand, inspired by Mitsubishi Lancer Evolution technology) are standard features on many trucks and trailers.
But here’s the bigger question: If a single cyclist’s observation led to such transformative changes, what other everyday problems are waiting for their Saltzman moment? And should we be doing more to apply space-age engineering to terrestrial challenges? Let us know your thoughts in the comments—we’d love to hear your take on this intersection of innovation and practicality.
