Cars travel across a highway bridge topped with a green girder structure
Traffic entering Maine on Interstate 95. Credit: Jimmy Emerson / Creative Commons

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.”

Annie is an independent climate journalist based in Midcoast Maine, where she is a regular contributor to The Maine Monitor and other publications. She previously spent a decade as an award-winning local public media reporter and host, including for New Hampshire Public Radio, where she created the newsroom's climate desk, led regional climate collaborations for the New England News Collaborative, reported for NPR and co-hosted the podcast series Windfall.