“I started on a train that took people to work,” remarked the Medford, Mass.-born travel writer Paul Theroux, as he embarked on the Orange Line to begin a long train journey from Boston to the tip of South America. Boarding at the newly opened Wellington station in the late 1970s, Theroux joined the 100,000 other daily Orange Line passengers on a line midway through a modernization project that would see both ends of the line entirely replaced.