Over the next decade, the decisions Colorado and other states make about how many new roads to build could have major implications for America’s ability to tackle climate change. Transport is the largest source of greenhouse gases in the country, producing 29 percent of emissions, and it is stubbornly difficult to clean up.
The new $1 trillion infrastructure bill invests billions in climate-friendly programs such as electric car chargers and public transportation. But it also gives states $273 billion for highways over five years, with few liabilities. An analysis by the Georgetown Climate Center found that this money could significantly increase emissions if states continue to add highway lanes.
There are already signs that even states with ambitious climate goals like Washington, Illinois and Nevada are hoping to use federal funds to expand roads, such as adding lanes to a congested section of the Eisenhower Freeway near Chicago. In 2019, states spent a third of their highway dollars on new road capacity, about $19.3 billion, with the rest spent on repairs.
“This is a big blind spot for politicians who say they care about climate change,” said Kevin DeGood, director of infrastructure policy at the Center for American Progress, a liberal think tank. “Everyone understands that oil pipelines are carbon infrastructure. But new highways are also carbon infrastructure. Both lock out 40 to 50 years of emissions.”
The core problem, environmentalists say, is a phenomenon known as “induced traffic demand.” When states build new roads or add lanes to overcrowded highways, instead of cutting traffic, more cars appear to fill available space.
The induced demand explains why, when Texas widened the Katy Freeway in Houston to more than 20 lanes at a cost of $2.8 billion in 2011, congestion returned to its former level within a few years.
“It’s not always intuitive to people, but the economic logic is pretty simple: If you make driving easier, people will do more of it,” said Susan Handy, a transportation expert at the University of California, Davis, who helped develop of a calculator show how highway expansions can increase emissions in different cities.