CityBus is one of the three major bus operators in Hong Kong, it provides both franchised and non-franchised bus services. The franchised route network serves mainly Hong Kong Island, cross-harbour routes (between Hong Kong Island and Kowloon/New Territories), Ocean Park, North Lantau (Tung Chung and Hong Kong Disneyland) and Hong Kong International Airport. The non-franchised routes serve mainly City One Shatin.

Citybus 2200 was one of three prototype Dennis Trident's to enter service with Citybus, and was built with an Alexander ALX500 body. It was one of the first low floor double-deck buses to enter service in Hong Kong and was used on some of Hong Kong's most demanding routes. These routes operate over some of the most hilly terrain of Hong Kong Island, at high frequencies, twenty-four hours a day and carry an average of 30,000 passengers a day. This makes them ideal for testing the new features of these buses which include - no steps in the entrance or exit, a kneeling facility to lower the front entrance, and a wheelchair space.