To Really Cut Carbon Emissions, Stop Building New Roads

UK freeways crisscross over each other.
UK freeways crisscross over each other.
Photo: Christopher Furlong (Getty Images)

The UK has big plans for electric vehicles. It aims to phase out of sales of all fossil fuel-run cars by 2035 in an effort to lower carbon pollution. But there’s another source of emissions that could wipe out most of the gains: new roads.


Earlier this year, researchers found that the shift to all-electric vehicles would cut the UK’s emissions by more than 10%. According to a new report from Transport for Quality of Life, though, 80% of that reduction will be negated by the emissions from the country’s multi-billion dollar roads program. The lessons from the report aren’t just for the UK but any country looking to reduce its transportation emissions.

The UK’s Road Investment Strategy 2 commits the country to investing $30.5 billion into constructing new roads over the next five years. It’s been billed as the largest ever roads expenditure program the country has ever seen, but it could undo climate progress. Using data from the government-owned firm Highways England, the report estimates that one third of the predicted road-building emissions would come from construction, including producing the steel, concrete and asphalt used. Building and construction are responsible for 39% of all global carbon emissions. Another third would come from the increased vehicle speeds on roads with higher speed limits. Driving faster emits more carbon because speed puts more strain on engine and can contribute to aerodynamic inefficiencies.

The final third would come from the extra traffic created by the planning responses to the new roads. Research shows that when you build more highways, people start driving more and filling up the lanes in a matter of years, in large part because planners respond to the road construction by creating of more car-dependent homes and more business parks to drive to.

“Electric cars ... can give us the space to think that we can keep doing the things we’ve been doing in terms of how we think of mobility and how we build infrastructure, and still slow climate change,” Shoshanna Saxe, an assistant professor in the University of Toronto’s Department of Civil and Mineral Engineering, told Earther. “But what we find consistently is that that doesn’t work, because even if a car had zero emissions ... coming out of its tailpipe ... building for cars is a problem.”

The study’s authors focus on the UK, but civic leaders elsewhere—including here in the U.S.—should take the report’s lessons to heart. Currently, localities across the U.S. are considering funneling resources into highway expansion programs.


Rather than pouring billions into roads and claiming that electric vehicles are path to decarbonization, the report authors say civic leaders should instead fund public transit, programs to make the UK more walkable and bikable, and a universal fast broadband program to support remote work. The same principles should be applied to other high-income countries, too.

“This report highlights the limits of a technology-focused approach to tackling climate change in the transportation sector,” Billy Fleming, the director of the University of Pennsylvania’s McHarg Center, told Earther in an email.


But as much as many of us would like to ban cars, doing so immediately would come with massive complications. Globally, entire urban centers are built in a car-centric manner, making people reliant on their personal vehicles.

“People build their lives around these infrastructure systems that the government has been funding for decades,” said Saxe. “We have to think about how we transition away from that ... so we’re not stranding people thoughtlessly.”


A report Fleming co-authored for Data for Progress last year calls for governments to not fund any new highway expansion until they’ve completed all necessarily maintenance and repair work for existing roads. At the same time, the report calls for more investment into lower-carbon transit options, like buses, trains, walking, and biking.

This would not only help draw down carbon emissions in a country where the transit sector is a top contributor to the climate crisis, it would also promote equity. Thanks to a long, racist history of segregation, highways are more likely to be constructed near Black communities where residents are more likely to breathe polluted air.


“Halting the endless expansion of highway systems is one of the only ways to tackle the complex of fossil fuel, real estate development, and private equity funds that are reproducing and exacerbating injustice and inequality within and between our communities,” Fleming said. “Electric vehicles are great, but they’re a relatively modest component of anything resembling a Green New Deal for Transportation. The harder, and more important work, rests in halting the never-ending expansion of highways systems that induce more people to drive, are incredibly carbon-intensive to construct, and consume valuable farmland and biodiverse habitat outside of our urban centers.”

Staff writer, Earther


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I agree in concept, but the US is a suburb nation. Share of US population: urban, 31%; suburban, 55%; and rural 14%. The fastest growing areas in the US are suburban and that may accelerate. So we may need some realpolitik on this. And maybe a new modern monetary theory to pay for new modern modes of suburb to suburb to urban-center transport.

It would be nice if new roads” were better defined. For example, is a complete redoing of the Eisenhower Expressway (from Chicago loop to the western suburbs) a new road project? This project is inching its way through feasibility study and public review. It includes massive improvements to and extension of the CTA Blue Line, which runs down the middle of the expressway. 

Fun with numbers:

From the DoT Office of Highway Policy Information, Highway statistics for 2018 (Table VM-1):

Vehicle Miles Traveled: 3,240,327,000,000 (3.2 trillion)

Number of vehicles registered (all types): 273,602,100 (273 million)

Average Miles traveled: 11,843

Total fuel consumed (gasoline and diesel): 178,130,339,000 (178 billion) gallons

Average MPG: 18.2