how was it planned?
Plans to expand the Portland Streetcar east of the Willamette River emerged in July 1997
Loop Service
Plans to expand the Portland Streetcar east of the Willamette River emerged in July 1997, at the same time the Portland City Council authorized the construction of the system's first line on the west side between Northwest Portland and PSU. 
what is a loop service? A streetcar circle route
wiki:10102398
Loop Service [SEP] Planning
Plans to expand the Portland Streetcar east of the Willamette River emerged in July 1997, at the same time the Portland City Council authorized the construction of the system's first line on the west side between Northwest Portland and PSU. During this time, the council also voted to fund a $16.7 million retrofitting of the Hawthorne Bridge, which they had hoped would carry a future eastside streetcar line between OMSI and the Oregon Convention Center as proposed by the Buckman Neighborhood Association. The Hawthorne Bridge reopened in April 1999, with the outer-lane decks rebuilt to accommodate notches for rails. In July 2001, the Lloyd District Development Strategy proposed another streetcar plan that sought the addition of streetcars to the Lloyd District, which was already being served by buses and MAX Light Rail, to create a transit hub by adding lines on Broadway and Weidler streets.