Auto emissions have risen nationwide in the last three decades, and particularly so in Fairfield County and Greater New Haven.

Auto emissions have gone up 25 percent overall in Fairfield County since 1990. When adjusted for population, that increase drops to 9 percent, according to Boston University’s Database of Road Transportation Emissions.

In New Haven, the increase is more stark. Overall, emissions have risen 41 percent since 1990 — a 32 percent per-person increase.

That pattern holds true across the country, according to a New York Times analysis of the Boston University data. Suburban driving is the primary culprit, and though there are more cars in denser, urban areas, there also tends to be more public transportation.

Auto emissions are, according to the Environmental Protection Agency, the largest producers of carbon monoxide and other greenhouse gasses. Passenger cars and SUVs make up 60 percent of all emissions, with another 23 percent coming from freight trucks, The New York Times reported.

Americans have been driving a lot more in recent years, according to federal officials, bolstered by a relatively solid economy and low gas prices.

In 2018, Americans drove 3.225 trillion miles, an increase of 12.2 billion miles over 2017, according to the U.S. Department of Transportation.

“Record-setting vehicle-miles traveled reflects a robust economy, lower gas prices and is another reason to ensure that America’s roads and bridges are well-maintained and modernized to improve safety,” U.S. Transportation Secretary Elaine L. Chao said.

Connecticut Media Group