or () for those with airline tickets or public transportation cards. A round-trip ticket costs (), and VIP tickets cost double the standard fare. With the first tram line been in service in 1908, trams were once popular in Shanghai in the early 20th century. By 1925, there were 328 tramcars and 14 routes operated by Chinese, French, and British companies collaboratively, all of which were nationalized after the PRC's victory in 1949. Since the 1960s, many tram lines were either dismantled or replaced by trolleybus or motorbus lines; the last tram line was demolished in 1975. Shanghai reintroduced trams in 2010, as a modern rubber-tire Translohr system in Zhangjiang area of East Shanghai as Zhangjiang Tram. In 2018, the steel wheeled Songjiang Tram started operating in Songjiang District. Additional tram lines are under planning in Hongqiao Subdistrict and Jiading District . Shanghai also has the world's most extensive bus network, including the world's oldest continuously operating trolleybus system, with 1,575 lines covering a total length of by 2019. The system is operated by multiple companies. Bus fares generally cost (). , a total of 40,000 taxis were in operation in Shanghai. The base fare for taxis is (), which covers the first and includes a () fuel surcharge. The base fare is () between 11:00 pm and 5:00 am. Each additional kilometer costs (), or () between 11:00 pm and 5:00 am. Taxicabs and DiDi play major roles in urban transportation and DiDi is often cheaper than taxis. As of January 2021, Shanghai Metro has 459 stations and 772 km. The scale of operation is the first in the world. in 2017, the average daily passenger traffic of the Shanghai metro was 9.693 million, and the total passenger traffic reached 3.538 billion. It is one of the busiest metro cities in the world. The metro lines cover the central city densely and connect most districts and counties. Roads and expressways Shanghai is a major hub of China's expressway network. Many national expressways (prefixed with the letter G) pass through or end in Shanghai, including Jinghu Expressway (overlaps with Hurong Expressway), Shenhai Expressway, Hushaan Expressway, Huyu Expressway, Hukun Expressway (overlaps with Hangzhou Bay Ring Expressway), and Shanghai Ring Expressway. There are also numerous municipal expressways prefixed with the letter S. As of 2019, Shanghai has a total of 12 bridges and 14 tunnels crossing the Huangpu River. The Shanghai Yangtze