Critics, studies cast doubt on Maine’s claims of climate benefits from highway expansion

The state says a proposed bypass outside Portland will reduce emissions by alleviating gridlock. Advocates say this claim has been disproven. 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...