The South Lake Union Streetcar, officially the South Lake Union Line, is a streetcar route in Seattle, Washington, United States, forming part of the Seattle Streetcar system. It travels and connects Downtown Seattle to the South Lake Union neighborhood on Westlake Avenue, Terry Avenue, and Valley Street. The South Lake Union Streetcar was the first modern line to operate in Seattle, beginning service on December 12, 2007, two years after a separate heritage streetcar ceased operations. The streetcar line was conceived as part of the redevelopment of South Lake Union into a technology hub, with lobbying and financial support from Paul Allen and his venture capital firm Vulcan Inc. The $56 million project was funded using a combination of contributions from local property owners, the city government, and grants from the state and federal government. Construction began in July 2006 and was completed over a year later by the Seattle Department of Transportation. The line is owned by the City of Seattle, with operation and maintenance contracted out to King County Metro. The line is popularly known by its nickname, the South Lake Union Trolley (abbreviated as "SLUT"), which is used on unofficial merchandise sold by local businesses. The streetcar was controversial in its first few years due to its slow speed, low ridership, public funding, and connections to real estate development. Improvements to the streetcar's corridor since 2011 have increased service and improved schedule reliability, but ridership has declined since peaking in 2013. A planned streetcar project to connect the South Lake Union Line with the First Hill Line via Downtown Seattle was placed on hold by the city government in 2018. History Earlier streetcars and planning The first electric streetcar to run along Westlake Avenue was operated by the Seattle Electric Railway and Power Company and opened five days after the company was awarded the city government's first streetcar franchise in October 1890. The Westlake streetcar line continued north from Downtown Seattle to the Fremont Bridge and was privately operated until being acquired by the city during the formation of the Seattle Municipal Street Railway in 1918. The streetcar system was gradually replaced with buses and the Westlake Avenue line ended service on April 13, 1941. Streetcar service in Seattle resumed in 1982 with the opening of the Waterfront Streetcar line along Alaskan Way, but the heritage streetcar ceased operations in 2005. Restoration of streetcar service within the