The New York Times published findings from an analysis of new data released through Boston University’s Database of Road Transportation Emissions. The map embedded in the report shows a year’s worth of CO2 from passenger and freight traffic on every road in the United States. From the report: The database provides the most detailed estimates available of local on-road CO2 over the past three decades. Even as the United States has reduced carbon dioxide emissions from its electric grid, largely by switching from coal power to less-polluting natural gas, emissions from transportation have remained stubbornly high. The bulk of those emissions, nearly 60 percent, come from the country’s 250 million passenger cars, S.U.V.s and pickup trucks, according to the Environmental Protection Agency. Freight trucks contribute an additional 23 percent.
Reducing emissions from driving has been a big challenge, said Conor Gately, who led the project mapping CO2 on America’s roads as a postdoctoral researcher at Boston University. Emissions dipped during the recession of the late 2000s, but have been ticking back up since 2013. National fuel economy standards put in place under the Obama administration have helped temper the rise in automotive emissions because the rules require cars and trucks to use less gasoline per mile traveled. But even as vehicles have become more efficient, Americans, buoyed by a strong economy and low gas prices, have been driving more miles and buying more S.U.V.s and pickup trucks, which have lower gas mileage. Freight trucking is also on the rise. Boston University’s emissions database, first published in 2015 and updated this week with an additional five years of data, reveals that much of the increase in driving-related CO2 has occurred in and around cities. The report goes on to say that in nearly every metro area, total emissions have increased since 1990. “The New York area, home to 20 million Americans, accounted for the largest share of driving-related CO2,” reports The New York Times. “After years of increase, emissions ebbed during the late-2000s recession but rebounded by 2017. In more car-dependent areas, like Dallas-Fort Worth, emissions from driving barely dipped during the recession and have increased rapidly in recent years. But, adjusted for population, these cities flip: Residents in the denser, more transit-friendly New York area contribute far less CO2 from driving on average than their counterparts in Dallas.”
As for how the database was created, “Boston University researchers used federal traffic data to calculate the number of miles travelled on local segments of each road in the United States and converted those miles to carbon dioxide emissions by estimating how much fuel is consumed by different types of vehicles using those roads.”