TriMet named the new service to the airport the Red Line to differentiate it from the established service between Hillsboro and Gresham , which was renamed the Blue Line . The Airport MAX extension opened on September 10 , 2001 . Celebrations slated for September 15 – 16 were canceled in the aftermath of the September 11 attacks , and the airport was closed for three days as a result of a nation-wide ground stop . The Red Line originally terminated at the Library and Galleria stations in downtown Portland , where its trains turned around at the 11th Avenue loop tracks . It replaced bus route 12 – Sandy Boulevard as TriMet 's only service to and from the airport from 2001 to 2018 , after which TriMet introduced 272 – PDX Night Bus , which operates in the late night and early morning hours when the Red Line is not operating . C-Tran service from Vancouver across the Columbia River was moved from its connection at Gateway Transit Center to Parkrose/Sumner Transit Center . Although tested during trial runs , TriMet opted to omit luggage racks from Red Line trains to maximize rider capacity . By November 2001 , ridership averaged at 2,300 riders and peaked at 3,800 a day before Thanksgiving holiday weekend . All service had been using single light rail cars , but this influx of riders prompted TriMet to temporarily deploy two-car consists for the first time , which it had not previously planned to do until 2006 . Regular use of two-car trains on the line began in September 2005 , when overcrowding prompted TriMet to change most Yellow Line service from two-car consists to single cars in order to convert the Red Line to two-car trains
September 11 attacks
September 11 attacks
MAX Red Line