MAX Green Line

The MAX Green Line is a light rail line serving the Portland metropolitan area in the U.S. state of Oregon. Operated by TriMet as part of MAX Light Rail, it connects Portland State University (PSU), Portland City Center, Northeast Portland, Southeast Portland, and Clackamas. The Green Line travels 15 miles (24.1 km) from the PSU South stations to Clackamas Town Center Transit Center and serves 30 stations. It is the only service that interlines with all of the other MAX services, sharing the Portland Transit Mall segment with the Orange and Yellow lines and part of the Eastside MAX segment with the Blue and Red lines. South of Gateway Transit Center, the Green Line branches off to Clackamas Town Center. Service runs for 21 hours on weekdays and 20 hours on weekends with headways of up to 15 minutes. It is the third-busiest line in the system with an average of 13,030 riders per day on weekdays in September 2024.

Planning for light rail in Clackamas County began in the mid-1980s with a proposal to build two separate lines, of which one was envisioned between Portland International Airport and Clackamas Town Center along Interstate 205 (I-205) via the I-205 busway. Feasibility studies conducted in the early 1990s shifted plans away from I-205 and culminated in the South/North Corridor project, which failed to secure voter-backed funding over several ballot measures.

In 2001, regional planners announced the South Corridor Transportation Project, a two-phased revision of the South/North project that proposed light rail along I-205 and the Portland Transit Mall in its first phase. With the support of local residents, the I-205/Portland Mall Light Rail Project was approved in 2003, and construction began in early 2007. The segments opened separately starting with the Portland Transit Mall in August 2009 and I-205 a month later. Green Line service commenced on September 12, 2009.

TriMet had intended to extend MAX to Southwest Portland, Tigard, and Tualatin with the Southwest Corridor Light Rail Project. The 13-station, 11-mile (18 km) extension would have begun construction in 2022 and opened in 2027 with service from the Green Line. On November 3, 2020, voters declined a tax ballot measure that would have provided local funding and put the project on hold.