the board approves a series of service reductions, to take effect in September. The board votes on August 12 to discontinue Fareless Square for bus service beginning in January 2010, while retaining fare-free rides in the downtown area on MAX and the Portland Streetcar. 2009 On August 30, MAX service on the transit mall is introduced, with the shifting of the Yellow Line to the new alignment. September 12 brings the opening of the Green Line, also using the new transit-mall tracks, running from downtown (PSU) to Clackamas Town Center. It is TriMet's first light rail line serving Clackamas County. 2010s 2012 TriMet purchases 55 new Gillig diesel buses to begin replacing buses dating back to 1990. The last four of the new buses are hybrid-electrics estimated to be 20-50% more fuel-efficient and produce 95% fewer emissions; they replaced hybrid buses that were in service since 2002. 2012 TriMet discontinues "Free Rail Zone" (formerly known as the "Fareless Square") in Downtown Portland and ends use of three-zone, distance-based fare system. Until this time, the TriMet district was divided into three fare zones, with fares based on the number of zones in which a passenger traveled. 2015 TriMet opens the new MAX Orange Line from Downtown Portland to Milwaukie, and the Tilikum Crossing, used by the Orange Line and two bus lines 2018 After 32 years without any all-night transit service, TriMet extends service hours on lines 20-Burnside/Stark and 57-TV Highway to run 24 hours a day. The agency also establishes Line 272-PDX Night Bus to provide early-morning service between NE 82nd Avenue and the Portland International Airport. 2019 TriMet introduces a new paint scheme, the first such change since 2002. 2019 TriMet's first battery-electric buses, numbered 3801–3805, go into service. 2020s TriMet's 14-mile Frequent Express line opens. 31 60-foot Novabus LFSA buses are put into service for use on the line. 2022 TriMet's Type 6 trains arrive for testing. Future TriMet works with local jurisdictions and agencies to identify and recommend priority transit projects to include in Metro's Regional Transportation Plan (RTP). The 2018 RTP is Metro's latest iteration, and it lists three funding scenarios that divide the region's proposals into three priority levels. The highest priority projects, which are referred to as "2027 Constrained", are proposals the region expects to have funding for by 2027. The "2040 Constrained" lists projects that fit within the region's planned budget through 2040,