As Maine considers building a new toll highway to improve commutes in and out of Portland, a state climate working group is drafting strategies to reduce driving in the state.

State officials say the two efforts are not inherently at odds, but experts and advocates caution that continued highway expansion could reverse climate progress by encouraging more people to drive.

The parallel discussions in Maine raise a question that few states have yet grappled with: can governments keep expanding car infrastructure without putting climate goals out of reach?

Transportation is the largest source of greenhouse gas emissions in Maine and many other states. Electric vehicle adoption is growing, but not fast enough to solve the problem on its own, which is why an updated state climate plan is expected to include a new emphasis on public transit, walking, biking, and other alternatives to passenger vehicles.

Zak Accuardi, the director for mobility choices at the Natural Resources Defense Council, said the best way for states to invest in their road systems in the era of climate change is to not build new roads, but maintain and upgrade existing ones to accommodate more climate-friendly uses. 

“The states who are taking transportation decarbonization really seriously are really focused on reducing driving, reducing traffic,” Accuardi said, pointing to Minnesota and Colorado as examples. “Strategies that help support more people in making the choice to walk, bike or take transit — those policies are a really important complement to … accelerating the adoption of zero-emissions vehicles.” 

Slow progress on EV goals

Electric vehicles have been Maine’s primary focus to date in planning to cut back on transportation emissions. Goals in the state’s original 2020 climate plan included getting 41,000 light-duty EVs on the road in Maine by next year and 219,000 by 2030. The state is far behind on these targets. The climate council’s latest status report said there were just over 12,300 EVs or plug-in hybrid vehicles in Maine as of 2023. 

A 2021 state clean transportation roadmap for these goals recommended, among other things, the adoption of California’s Advanced Clean Cars II and Advanced Clean Trucks rules, which would require an increasing proportion of EV sales in the coming years. 

Maine regulators decided not to adopt Clean Cars II earlier this year in a 4-2 vote. A subsequent lawsuit from youth climate activists argued the state is reneging on its responsibility to meet its statutory climate goals by choosing not to adopt such rules. 

The original climate plan also aimed to cut Maine’s vehicle miles traveled (VMT), which measures how much people are driving overall, by 20% by 2030. The plan said getting there would require more transit funding, denser development to improve transit access, and broadband growth to enable remote work, but included little detail on these issues. It did not include the words “active transportation” at all. 

That appears poised to change in the state’s next four-year climate plan, due out in December. Recommendations from the state climate council’s transportation working group have drawn praise from advocacy groups like the Bicycle Coalition of Maine. 

New detail on non-car strategies

The group’s ideas include creating new state programs to support electric bike adoption, including in disadvantaged communities; paving 15 to 20 miles of shoulders on rural roads per year to improve safe access for cyclists and pedestrians; and, depending on federal funds, building at least 10 miles of off-road trails in priority areas by 2030. 

The group also recommended the state “develop targets related to increased use of transit, active transportation, and shared commuting that are consistent with Maine’s statutory emissions reduction goals.” 

In unveiling the recommendations, working group co-chair and Maine Department of Transportation chief engineer Joyce Taylor noted community benefits from road safety upgrades to accommodate these goals. 

“I think this also gets at housing and land use,” she said. “If you can get people to want to live in that community, that village, I think we could all say that it’s more economically vibrant when people are able to walk and bike in their village and feel like they can get around and it’s safe.” 

The Gorham Connector project would offer a new, tolled bypass around local roads as an alternative to upgrading those existing routes, an option that’s also been studied. State officials say the new road would smooth the flow of local traffic, including public transit. 

Towns aim to marry transit, housing, climate

Towns like Kittery, in southern Maine, have tried to focus on a more inclusive array of transportation strategies in their local work to cut emissions from passenger vehicles. 

Kittery town manager Kendra Amaral is a member of the climate council’s transportation group. She couldn’t comment on the state’s approach to the Gorham Connector, which is outside her region. But she said her town’s climate action plan, adopted this past May, “threads together” public transit, housing growth and emissions reductions. 

Stakeholders who worked on the plan, she said, strongly recommended ensuring that housing is in walkable or transit-accessible places. 

Amaral said the town has invested in new bus routes, commuter shuttles and road improvements to promote traffic calming and create safer bike and pedestrian access, as well as in EV growth. And she said Kittery was a model for parts of a new state law that enables denser housing development. 

“We can’t expect people to reduce (emissions) resulting from transportation without giving them options,” she said. But, she added, “there is no ‘one size fits all’ solution” for every community. “I believe we have to avoid the ‘all or nothing’ trap and work towards (the priorities) that get the best results for each community,” she said. 

‘Devil is in the details’

The Maine Turnpike Authority acknowledges the proposed Gorham Connector project in the Portland area would increase driving. But paired with improvements to transit and land-use patterns, they say the proposed limited-access toll road would decrease emissions overall — though research and other cases cast doubt on this possibility. 

“It’s possible for a project like this to be designed in a way that does produce favorable environmental outcomes,” Accuardi said, but “the devil is really in the details.” 

For example, he said the new road’s tolls should be responsive to traffic patterns in order to effectively reduce demand. If they’re too low, he said, the road will become jammed with the kind of gridlock it aimed to avert. But set the tolls too high, and the road won’t get used enough. 

He said it’s true that this kind of new access road can lead to denser housing development in the surrounding area — but the road will need to be tolled carefully to account for that increased demand. 

And the proceeds from those tolls, he said, should ideally go toward new clean transportation alternatives — such as funding additional transit service or safe walking and biking infrastructure around the new toll road, helping to finance subsidized affordable housing in transit-served areas, or allocating revenues to surrounding towns that make “supportive land-use changes” to lean into transit and decrease driving. 

Maine has indicated that it expects to use tolls from the Gorham Connector primarily, or at least in part, to pay for the road itself and avoid passing costs to other taxpayers.

But Accuardi said alternative strategies should see more investment than road expansions in the coming years if states like Maine want to aggressively cut emissions. 

He said on average, across the country, states spend a quarter of their federal transportation funding on “expanding roads or adding new highway capacity.” 

“That’s more money than states tend to spend on public transit infrastructure, and that really needs to be flipped,” he said. “We need to see states really …  ramping down their investments in new highway capacity. Because, again, we know it doesn’t work.”

Can Maine meet its climate targets and keep expanding highways? 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.

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.