Taxis in Shanghai are plentiful and market competition has driven taxi fare down to affordable prices for the average resident (¥14〈 ¥18 after 11pm 〉for the first 3 kilometers).
Taking a taxi is a fast and convenient way to get around Shanghai. The city, has the best-managed taxi service in China.
Most cabbies know their way around and expertly negotiate the city's busy traffic. Taxis are usually readily available, but hailing one in rush hours is difficult and on rainy days almost impossible.
Shanghai's taxis are colorful, unlike New York City's, which are all yellow. Cyan, yellow, white, green, blue, red, dark blue and dark red are the main colors of the taxis in Shanghai and the colors denote different taxi companies. Dark blue and dark red are the colors for the city's hundreds of small and medium taxi companies.
Real taxis have a logo light on the top of the car. Around the driver's seat is a transparent shield protect the driver from robbery. A meter and an illuminated vacancy disk on the dashboard are also necessities for a cab. Without all these things, the taxi is probably unlicensed and you should avoid it, even if the driver solicits you. You have no rights if injured in an unlicensed taxi.
The vacancy disk will help you know which cab is available. When the disk is upright and illuminated showing two Chinese characters -- 空车 -- it means the cab is vacant.