used a variety of vehicles in its history, including horse-drawn streetcars, Peter Witt streetcars, the PCC streetcar, and the Canadian Light Rail Vehicle and its articulated counterpart, the Articulated Light Rail Vehicle. Since 29 December 2019, the system exclusively uses the Flexity Outlook made by Bombardier Transportation. Streetcars once existed in the Canadian cities of Calgary, Edmonton, Halifax, Hamilton, Kingston, Kitchener, London, Montreal, Ottawa, Peterborough, Quebec City, Regina, Saskatoon, Windsor, Winnipeg, and Vancouver. However, Canadian cities excluding Toronto, removed their streetcar systems in the mid-20th century. In the late 1970s and early 1980s, light rail systems were introduced in Calgary and Edmonton; with another light rail system established in Ottawa in 2001. There is now something of a renaissance for light railways in mid-sized cities with Waterloo, Ontario the first to come on line and construction underway in Mississauga, Ontario and Hamilton, Ontario. In the late 20th century, several Canadian locales restored portions of their defunct streetcar lines, operating them as a heritage feature for tourists. Heritage streetcar lines in Canada include the High Level Bridge Streetcar in Edmonton, the Nelson Electric Tramway in Nelson, and the Whitehorse Waterfront Trolley in Whitehorse. United States Pittsburgh had kept most of its streetcar system serving the city and many suburbs, making it the longest-lasting large-network streetcar system in the United States. However, most of the city's streetcar lines had been abandoned by the early 1970s, and the handful of surviving streetcar lines were converted to light rail in the 1980s. San Francisco's Muni Metro system is the largest surviving streetcar system in the United States, and has even revived previously closed streetcar lines such as the F Market & Wharves heritage streetcar line. In the late 20th century, several cities installed modern light rail systems, in part along the same corridors as their old streetcars systems, the first of these being the San Diego Trolley in San Diego in 1981. In the 1980s, some cities in the United States brought back streetcars lines, including Memphis, Tampa, and Little Rock; However, these streetcar systems were designed as heritage streetcar lines, and used vintage or replica-vintage vehicles. The first "second-generation streetcar systems" in North America was opened in Portland in 2001. The "second-generation streetcar system," utilizes modern vehicles – vehicles that feature low-floor streetcars. These newer streetcar systems were built in several American cities in the early 21st century including Atlanta, Charlotte, Cincinnati, Dallas,