Metro belongs to A professional organization much like cities, school boards, mayors, state department heads, governors, etc. when they meet and discuss issues pertinent to their position(s). Then the group-think takes over.
Metro is part of NARC, an unfortunate acronym for National Association of Regional Councils - "Building Regional Communities". There are 12 MPOs (Metropolitan Planning Organizations) and COGs (Council of Governments) in Oregon - including SW Washington. On the map of the US showing where MPO & COGs exist, there is precious little land not covered by a colored splotch. If there's a town anywhere with a grocery store and two taverns in it, it's covered.
"As the Metropolitan Planning Organization for the Portland region, Metro is authorized by Congress and the State of Oregon to coordinate and plan investments in the transportation system for the three-county area. Metro uses this authority to expand transportation options, make the most of existing streets and improve public transit service."