In the 1970s, SOM collaborated with landscape architect Lawrence Halprin to plan and design the Portland Transit Mall. The goals were to revitalize the Oregon city's downtown area, to encourage the use of mass transit, and create walkable streets. The Transit Mall helped to change the perception of downtown Portland. As one of the first projects of its kind in the United States, it helped to usher in an era of streetscape design that prioritizes people. Another important commission in the 1970s was as the lead design firm for the Boston Transportation Planning Review, a metropolitan wide re-design of Boston's entire transit and roadway infrastructure.