While the DOT conducted the study to highlight the impact of dwindling revenue from the gas tax, which funds much of the country’s road maintenance, there’s a bittersweet upside to the very real and serious matter of a suffering transportation infrastructure.

Based on our quick, back-of-the-envelope calculation, 40.5 billion fewer miles in a country with an average nationwide fuel economy of 24.5 miles per gallon, equals an emissions reduction of about 31 billion pounds of carbon dioxide. That’s roughly equal to the CO₂ stored in 17.6 million acres of 25 year old maple-beech-birch forest, based on a Tufts University estimate.

That’s roughly the size of 18 Rhode Islands. That’s a lot of forest.

By no means are we downplaying the crippling effects of a sudden and steady rise in the cost of oil, but the DOT study does reveal what’s possible if we curb our driving habits even a little bit.