Getting behind the wheel of my 2013 Subaru turns me into a bit of a troll—just not the kind you might think. I’m not a tailgater, and I don’t honk. I’ll always let you merge, likely with one of those two-fingered courtesy waves ubiquitous on country roads where I live in Vermont.

But I am slow. I often drive five under the speed limit on the interstate, cruising through the Green Mountains at an unhurried 60 miles per hour. I take it pretty easy through towns. In a country where more than 70 percent of drivers admit to exceeding legal speed limits, that makes me an outlier. (Probably a little annoying too; that’s where the troll part comes in.) 

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I have good reasons for being poky, ranging from safety concerns to environmentalism. If you hit a pedestrian, the odds of killing them soar with speed: Fatality rates are 40 percent at 30 mph, double to 80 percent at 40 mph, then spike to nearly 100 percent when you’re driving 50 mph. The National Highway Traffic Safety Administration estimates that speeding is a factor in a one-third of motor vehicle fatalities. Easing off the accelerator reduces animal-vehicle collisions that contribute to some species’ extinction risk. Driving more slowly also releases fewer greenhouse gases. A 2020 report from the German Environment Agency found that enforcing a 100-kilometer-per-hour (62-mph) highway speed limit would decrease the famously speedy country’s annual greenhouse gas emissions by the equivalent of 5.4 million tons of carbon dioxide. Such a reduction would be like taking 1.2 million cars off the road.

But in a time of rising gas prices and high inflation, slowing your roll could also translate to saving some serious cash. That’s because cars are more efficient at slower speeds, when the drag that air exerts on a vehicle—air resistance—goes down along with tire-rolling resistance (the work required to keep your wheels turning). While the optimal speed varies with each car model, fuel economy generally takes a steep dive at speeds above 50 mph, according to the EPA. 

For your pocketbook, the difference can be dramatic. As I write this, the average price per gallon for gasoline in the United States is $4.75. (It’s worth noting that this price does not reflect gasoline’s true environmental and human costs; in 2011, the nonprofit Center for Investigative Reporting calculated that accounting for such externalities would put the price per gallon closer to $15.)

The EPA fuel-economy calculator shows that at today’s prices, a 100-mile trip at a laid-back 60 mph would cost me $11.01 in gasoline, a price of 11 cents per mile. Rushing along at a more socially acceptable 75 mph would get me there 20 minutes faster, while costing a total of $14.08, a price increase of 28 percent. 

Cost per 100 Miles = Fuel Price ÷ Estimated MPG × 100

That’s a significant jump. The average US driver puts 13,476 miles on their car each year, according to the most recent data from the US Department of Transportation’s Federal Highway Administration. For simplicity’s sake, I’ll imagine that it’s all at highway speeds: In my own aging Subaru, driving that far at 60 mph would cost $1,484 in gasoline. Speeding up to 75 mph would pump my annual gas bill up to $1,897. 

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Speed isn’t the only factor that affects your vehicle’s fuel economy. If you have a cargo box on top of your car, the EPA estimates it could lower your fuel economy by 10 to 25 percent at highway speeds. Using cruise control, on the other hand, can help. So does forgoing fuel-gobbling aggressive driving behaviors. 

“Aggressive accelerations, heavy braking, and driving too fast all worsen your fuel economy,” said John Heywood, an emeritus professor at MIT’s Department of Mechanical Engineering. Avoiding these is something of an obsession for the “hypermilers,” a subculture of drivers who share tips on how to maximize their cars’ fuel economy. In online forums, such hypermilers swap advice on techniques such as driving without brakes ("DWB" in hypermiler jargon), a term for coasting toward stops to make the most of a vehicle’s inertia. 

But most Americans aren’t hypermilers, and even the widespread financial pain of higher gasoline prices doesn’t seem to be slowing us down. In 2021, driving-related deaths per mile traveled rose by 7.2 percent, and the percentage of speeding-related deaths rose by 11 percent. Reckless driving, like speeding and driving while intoxicated, has gone up too. 

I haven’t always been a cautious driver either. For the most part, I slowed down because of my experiences outside the car. As an avid cyclist, I know how scary it is when a car speeds past me on a two-lane road; I worry about my husband, pedaling a country highway to the farm where he works. It was only after slowing down that I learned just how many reasons there are to avoid high speeds. 

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And as I’ve discussed the issue with experts, I’ve heard again and again that changing our country’s driving habits will not be easy. Telling people to drive differently is sensitive, and cars have long occupied an oversize place in US culture. Aggressive driving is a public health problem, but it’s one that comes wrapped in the flag and defended as individualism.

Americans have an “idea of ourselves as restless and accumulating and successful and getting things done. That idea of the activeness of our identities—the car is a perfect symbol for that,” said anthropologist Catherine Lutz, coauthor of the book Carjacked: The Culture of the Automobile and Its Effect on Our Lives. Going fast, she added, is associated with power, potency, and, for some, machismo.

And while driving over the speed limit is against the law, Lutz said that many Americans see skirting enforcement as a natural response. “It’s this idea that, ‘Well, the cops are going to be there, but we’re getting around them constantly.' And we take it for granted,” she said. “It’s not that you’re breaking the law; you’re ‘dealing’ with the law.” Though automated enforcement using speed and red-light cameras is one solution—and some argue that it can also reduce racial bias in traffic policing—such tools have faced opposition and even bans in some parts of the United States. 

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But if changing the way Americans drive seems far-fetched, it’s not without precedent. After an OPEC-led oil embargo sparked the 1973 oil crisis shortages and soaring prices, President Richard Nixon signed the Emergency Highway Energy Conservation Act, which included a provision to limit US highway speeds to 55 mph. As he signed the bill, Nixon quoted estimates that the United States could save almost 200,000 barrels of fuel a day by slowing down to 55. And for a time, we did. In the ensuing year, traffic fatalities declined by 16.4 percent. 

Individual actions can’t replace the systemic need for better transportation alternatives. The United States needs more public transit, and streets that are safer for both pedestrians and cyclists. But in the meantime, slowing down can dial back a little of the harm we’re causing in our cars.  

"With the attitude of cooperation and mutual concern expressed by a wide range of conservation actions by individual Americans, the social and economic impacts of the energy crisis can be minimized,” Nixon said in 1974. I never thought I’d say this, but I think Nixon was right.