A Montgomery County Council member abandoned his push Thursday for single-tracking on the Purple Line after a new study found it would slow trains, reduce ridership and save few trees.

Councilman Roger Berliner, D-Bethesda, wanted a single track between Bethesda and Columbia Country Club in Chevy Chase, saying it could salvage trees along the planned, 16-mile light rail line. But he relented Thursday, effectively killing prospects for any single-track segments on the transit system that would connect the Bethesda and New Carrollton Metro stations.