The opening wasn't supposed to happen for another three and a half years. The 4-mile Orange Line extension from Canoga Park to Chatsworth was not only finished early, but it came in under budget by nearly $62 million.
The Orange Line connection connects the west San Fernando Valley to the Red Line subway in North Hollywood 18 miles away.
The original price to complete the project was $215.6 million. The actual cost to complete was $154 million. The money saved will go toward future transportation projects.
City officials and the media had a chance to preview the extension on Friday before it opens to the public on Saturday.
Los Angeles Mayor Antonio Villaraigosa attended the ribbon-cutting ceremony at the Sherman Way Station on Canoga Avenue.
According to Metro, with the extension, weekday ridership for the Orange Line will exceed 27,000 passengers.
Measure R, the voter-approved initiative that raised the sales tax in Los Angeles County 1 cent paid for the project.
Free rides will be offered from 7 a.m. to 7 p.m. Saturday and Sunday.