HONG KONG -- The tramways of China's Hong Kong Special Administrative Region unveiled a new logo and visual identity on Friday for its century-old tramcars, also known as Ding Ding car.

The background color of the new visual identity of tramcar is green, representing the tramcars are environmental and safe.

The new slogan, "catch a ride, catch a smile" is printed on the front of the tramcar. On the bottom of the vehicle, there is a smile expression, meaning tramcars' friendly personality and faithful service.

For the coming months, tramways is also going to make its 160 tramcars smile with an additional sticker on the bumper.

Besides this new graphic system, Hong Kong tramways also pledged to make its passenger information on stops and website more friendly.

As all tramcars are designed and built at tramways' depot by skillful and experienced craftsman in Hong Kong, to commend the hard work of them, tramways will install a bronze plate on board of each tramcar to remind the public of the unknown heroes.

Hong Kong tramways has been in service since 1904 and operates nowadays a fleet of 164 tramcars. It is the world's largest fleet of double-deck tramcars in operation, carrying about 200,000 passengers every day.