The Portland Bureau of Transportation has released a draft of the Portland Streetcar System Concept Plan, available at http://www.portlandonline.com/transportation/streetcarsystemplan. It identifies high priority and other potential future streetcar routes in Portland.
As it pertains to Buckman, there is a priority route from downtown heading out Belmont to 39th, then south to Hawthorne to 50th. Hawthorne is a potential alternate route.
The 45-day public comment period on the plan runs until August 14th (comment forms are available online at the link above), so please review it and make comments if you have an interest in (for, against, or neutral) the streetcar and the possibility of a line through Buckman. On August 11th, the Portland Planning Commission will hold a hearing on the plan and it will go before the City Council on September 9th.