Climate and clean transportation advocates are calling into question a claim by Maine officials that a new toll road proposed outside Portland will reduce carbon emissions by alleviating gridlock. 

It’s a common argument made in favor of highway expansions nationwide, said Benito Pérez, the policy director of the nonprofit Transportation for America. But it relies on a narrow view of data that, in context, tends to show these projects are more likely to increase planet-warming emissions, he said. 

“They’re looking at it from one dimension,” said Pérez, a former transportation planner and engineer. “This is a multi-dimensional issue when it comes to emissions reduction, and it’s not going to work.”  

Maine’s proposed Gorham Connector project has met stiff public opposition in its rollout over recent months. The toll road aims to offer a more direct route from Portland’s growing suburbs into the city, bypassing local roads that officials say weren’t designed to accommodate increasing commuter traffic.

The project has been contemplated since the late 1980s. Its latest iteration builds on a 2012 study that recommended three main ways to improve connectivity between Portland and points west: new approaches to land use and development, expanded bus and passenger rail access, and various road upgrades and expansions, including the new four-lane, roughly five-mile bypass the state is now proposing.  

The Maine Turnpike Authority took more than three hours of comments at its first public input session on the project in March. On July 18, the MTA said it would delay further public meetings on the project and extend its permitting timeline due to a “high level of public interest and concern.” 

In response to questions for this story, MTA spokesperson Erin Courtney emphasized the importance of a multi-pronged approach in achieving the Gorham Connector’s projected climate benefits. 

“Coupled with targeted land use and transit initiatives, we aim to create a more efficient and sustainable transportation system that addresses both congestion and environmental impacts,” she said.

Benefits are ‘negligible at best’

The emissions impact of smoother traffic on the proposed toll road has been one of the MTA’s core arguments in favor of the project. The agency says on the the website for the Connector that it “will ease traffic flow, decreasing the number of idling vehicles, conserving fuel, and reducing exhaust pollutants in alignment with Maine’s Climate Action Plan.” 

But even in isolation, this emissions benefit is typically “negligible at best,” said Pérez. Despite ongoing improvements in vehicles’ fuel efficiencies and even electrification, he said, studies show that more use of expanded roads tends to outweigh this benefit. 

Pérez pointed to examples in the Washington, D.C. area, Salt Lake City and elsewhere where highway expansions that aimed to reduce gridlock instead led to more traffic and further need for expansions years later — a paradox known as “induced demand.” 

A 2015 paper from the University of California-Davis explains this phenomenon: “Adding capacity decreases travel time, in effect lowering the ‘price’ of driving; and when prices go down, the quantity of driving goes up,” author Susan Handy wrote. New roads, for instance, can encourage more low-density development, which in turn fills those roads with additional drivers. This counteracts the value of highway expansions in alleviating congestion, Handy said, and at least partly offsets the emissions reductions that come along with it. 

Courtney, with the MTA, said “the Gorham Connector’s design and goals suggest a different outcome,” arguing that the project is unique as a limited-access highway without many intersections or entrances. 

“By enhancing traffic efficiency and reducing congestion on local roads, it can offer a balanced approach that considers both transportation needs and environmental impacts,” she said. 

Portland resident Myles Smith, a steering committee member with Mainers for Smart Transportation, a volunteer group opposing the Gorham Connector, isn’t convinced. 

“It’s part of a pattern of showing only the rosiest possible scenarios of how, theoretically, on paper, with a lot of other assumptions going perfectly, it might reduce climate emissions,” he said. “It assumes a lot of other things that they have no control over at the Turnpike Authority, like land-use planning and public transportation.”

New measures of climate impacts 

The 2012 study backing the bypass proposal found that implementing a bevy of suggested road improvements and expansions, including the Connector, would decrease local vehicle hours traveled, or VHT — an analog for congestion, measuring how much time people spend in their cars, Pérez said — by about 10% versus 2035 projections. 

It also said the area’s vehicle miles traveled, or VMT — which measures how much people are driving overall — would increase relative to 2035 projections if the bypass was built, but would decrease in scenarios where only existing roads were improved, or where public transit was the focus. 

“This is why we propose a ‘three-legged stool’ approach,” Courtney said — one that also emphasizes dense development and increased public transit access, so that VMT increases might be offset by other benefits. 

VMT is an increasingly common way to measure the climate benefits of transportation projects, Pérez said. Minnesota and Colorado have adopted new requirements toward goals for reducing their overall VMT, mandating that proposed road expansions either contribute to this decrease, or fund climate mitigation projects otherwise. 

But advocates said VMT and VHT alone are not enough to measure the overall climate impacts of a project like the Gorham Connector. A more comprehensive analysis, they said, would include the environmental impacts of construction and would account in more detail for the role of the non-road improvements that the MTA is also calling for. 

A need for coordinated solutions

The 2012 study, in its final recommendations, said all three strategies — changes to roads, transit and development patterns — would need to “work together to provide the desired results” for improving connectivity and reducing traffic impacts in the Portland area. For example, more dense development and less congestion will make new transit approaches more viable, Courtney said. 

The Turnpike Authority has little direct control over those kinds of reforms, but says on its website that it expects “other regional studies” in those areas to be part of the Gorham Connector planning process. 

“The Gorham Connector project, combined with additional initiatives being considered by the MTA and Maine (Department of Transportation) — such as additional park-and-ride facilities, electric vehicle charging stations, and enhanced transit opportunities — will collectively contribute to reduced greenhouse gas emissions compared to a ‘do nothing’ scenario,” Courtney said. 

Smith said these other efforts are moving more slowly and with less state support than the Connector has received, putting these parallel solutions out of step with each other. 

Maine is facing a lawsuit from youth climate activists over regulators’ decision earlier this year not to adopt California’s Advanced Clean Cars II rule, which would have ramped up requirements for electric and plug-in hybrid vehicle sales through model year 2032. 

The state is still a long way off from the EV goals set in its 2020 climate action plan, which also aims to reduce light-duty vehicle miles traveled 10% by next year and 20% by 2030. 

Advocates applauded a new emphasis on transit, biking, walking and other alternative strategies to achieve those VMT goals in the recommendations from a state climate council working group for a forthcoming update of the climate plan, due out in December. 

It’s an example of slow progress toward more holistic approaches to transportation and climate planning, which, Pérez said, must extend to technical details like the traffic models that underlie projects like the Gorham Connector in order to succeed. 

“Those models need to think about what they’re measuring — what matters most,” he said. “The mindset is, ‘we’re designing for vehicles,’ and that’s what they’re measuring for, not measuring for the movement of people.”

Critics, studies cast doubt on Maine’s claims of climate benefits from highway expansion is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.

The recent expansion of a groundbreaking transportation law in Minnesota means all major highway projects in the state will soon be scrutinized for their impact on climate emissions.

A year ago, the state legislature made headlines with a new law requiring the state transportation department and the Twin Cities’ regional planning agency to begin assessing whether highway expansion projects are consistent with state climate goals, including Minnesota’s aim for 20% reduction in driving by 2050.

A follow-up bill passed this spring expands the 2023 law to include all major highway projects statewide that exceed a $15 million budget in the Twin Cities or $5 million outside the metro, regardless of whether or not they would add new driving lanes. The updated legislation also established a technical advisory committee and a state fund to recommend and help pay for mitigation projects.

“It allows for some evolution of the law,” said Sam Rockwell, executive director of Move Minnesota, a nonprofit advocacy group that supported the legislation. “There’s more flexibility.”

The law requires transportation project planners to offset projected increases in greenhouse gas emissions and vehicle miles traveled to qualify for state or federal highway dollars. Those mitigation efforts might include incorporating funding for transit, bicycle or pedestrian programs or environmental restoration projects.

‘A waterfall effect’

Altogether, the law will now cover more than 12,000 miles of state trunk highways that account for more than 60% of all miles driven in the state. One high-profile project that may not have been covered under the initial law is the upcoming reconstruction of Interstate 94 between Minneapolis and St. Paul, which will now need to account for climate impacts.

The changes come as advocates and officials seek solutions to reverse the continued growth of transportation emissions, which surpassed electricity generation almost a decade ago as the state’s largest source of greenhouse gas emissions and are a major reason why Minnesota is not on track to meet its climate goals. 

A disconnect has long existed between even progressive states’ climate goals and the status quo of highway construction, which has long focused on maximizing efficiency for drivers. The new Minnesota law is an attempt to integrate climate action into state and local transportation planning, and to recognize that electric vehicles alone won’t be enough to achieve climate targets. 

Under the law, the Twin Cities’ regional planning agency, the Metropolitan Council, must include strategies for reducing greenhouse gas emissions and vehicle miles driven in its next 25-year regional plan in 2026. All metro area communities will then use that plan as the basis for their local comprehensive plans, which are due to the regional council in 2028. 

“It’s a waterfall effect here,” Rockwell said.

The Met Council’s last planning document, Thrive 2040, already outlined a focus on multimodal travel options, encouraging walking and biking options while setting a goal of decreasing vehicle miles traveled per capita by 20% by 2050, in line with the state’s official goal.

Conversations already underway

Many metro area communities are already having conversations about how to reduce dependency on driving. Abby Finis, a consultant who has helped several communities draft climate action plans, said reducing driving can bring broader benefits than simply focusing on electric vehicles.

“It offers more active lifestyles, more opportunities to incorporate nature, and has less impact on natural resources needed for electric vehicles,” she said.

Most communities focus on increasing the ability of residents to walk and bicycle for short trips by adding bike lanes, pedestrian islands and safer crosswalks, she said. Some cities see telecommuting and co-working spaces as options for reducing commutes.

But transforming the suburbs will be challenging, Finis said. Sustaining transit service often requires denser development, which continues to be politically controversial in many communities. 

“I have yet to see any community push hard on those strategies in a way that meets what is necessary to reduce [vehicle miles traveled] and adapt to climate change,” Finis said.

For example, Minnetonka, a western suburb of Minneapolis with more than 52,000 residents, boasts a considerable bicycling community. But transit ridership is low except for a modest ridership at the regional mall, one commercial development area, and park-and-ride lots, said Minnetonka’s Community Development Director Julie Wischnack.

Developed in the 1950s and 1960s, Minnetonka’s current land use is a barrier to fixed route transit. But the city is among a collection of suburbs along Interstate 494 that has been pushing for transit and other commuting options, including telework.

Another member of that commission, Bloomington, faces many of the same challenges. The city has a few dense neighborhoods near transit stops and the Mall of America, but much of the community remains single-family homes and small apartments. A recent report Bloomington commissioned on transportation found that 75% of trips by residents were more than 10 miles. 

Transit, biking, and other modes could replace trips that are less than 10 miles, said Bloomington Sustainability Coordinator Emma Struss. A recent city transportation study suggested several strategies to decrease driving, including transit-oriented development, free bus and rail passes, bike parking, subsidized e-bikes and more transit. Removing barriers to walking and biking were highlighted.

“We’re hearing more and more from residents that they want safe ways to get around the community without needing to take a car,” Struss said.

Similar challenges in larger cities

St. Paul has made changes to create denser neighborhoods, including removing parking minimums for new development and letting up-to-four-unit complexes be built in single-family neighborhoods. The biggest challenge continues to be the spread-out nature of the region, which forces people to drive to suburban jobs and big-box merchants. 

“The fundamental nature of those trips is hard to serve with anything but driving in the car,” said Russ Stark, St. Paul’s chief resilience officer.

Minneapolis has focused less on vehicle miles and more on “mode shift,” or decreasing trips, said the city’s Public Works Director Tim Sexton. The goal is to replace three of five trips by car with walking, biking, or other modes. A city transportation action plan features more than 100 strategies, including creating around 60 mobility hubs where residents can rent e-bikes, scooters or electric vehicles, or take transit.

Patrick Hanlon, the city’s deputy commissioner of sustainability, healthy homes and the environment, pointed out that Minneapolis has one of the country’s best-developed bike networks, which continues to grow. The city’s comprehensive plan drew national attention for removing barriers preventing denser development, which typically leads to fewer transportation emissions. Several transportation corridors now feature bus rapid transit lines.

What Finis described as a “patchwork” of conversations around developments like these are expected to become more comprehensive as the state law’s planning requirements take effect in the coming years.

The legislation has also made Minnesota a national inspiration for other states looking to make progressive changes to highway planning, Rockwell said.

“We know of a number of other states that are looking at trying to replicate parts of this (law), which is great,” he said. “We’ve been on the phone with folks from New York, Michigan, Illinois and Maryland who are trying to bring some pieces of this into their legislative sessions and their legal framework. That’s exciting.”

Minnesota highway projects will need to consider climate impacts in planning is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.