The subway is the second phase of the San Francisco Municipal Transportation Agency's Third Street Light Rail Project. The first phase opened to the public as the T Third line in 2007. Ground was broken for the Central Subway on February 9, 2010. Tunnel boring for the Central Subway was completed at Columbus and Powell Street in the North Beach neighborhood of San Francisco on June 11, 2014. Originally set to open in late 2018, the Central Subway is (as of November 2020) projected to open to the public in spring 2022. With the addition of the Central Subway, the T Third line is projected to become the most heavily ridden line in the Muni Metro system by 2030.