Records relating to the period before the 1930s are scarce as they were mostly destroyed in World War II, but the surviving photographic and written evidence indicates that an extensive network of buses served both sides of the harbour.
Buses of various British bus manufacturers, such as Leyland, Thornycroft and Daimler were present in significant numbers around the territory.
During the occupation, the Japanese tried to restore bus services to normal levels, but were unsuccessful due to an insufficient supply of fuel and spare parts.
This was because the Gardner engined double-deckers did not perform satisfactorily given the hilly terrain, and population levels on the island were more steady and predictable.
Areas like Wong Tai Sin, Kwun Tong and Chai Wan were developed at a rate that were unparalleled in any other British colony.
Soon, these behemoths – for their time – were dominating the Kowloon streets, and replaced older Daimlers in outer areas, as well as the Cross-Harbour Tunnel routes later.
Finally CMB ordered 40 36-foot single-deck buses to shift the working crowds, after considering their early success in Africa.
Those single-deckers, however, suffered from the same problem as their African siblings: They were too long, with a 10-foot overhang, 22-foot wheelbase and no upper deck to provide additional strength.
On KMB buses, there were up to four people employed on each bus – a driver, one or two conductors to collect the fares and the last, the gateman, supervised boarding and alighting by opening and closing the gates at each end.
In 1968, two new towns, Kwun Tong and Tsuen Wan, started flourishing and KMB extended its service by opening a new route 40 to and from these.
In the same year, CMB also decided to convert its Guy Arab MkV single-deckers to double-deckers after one caught fire in 1968.
Some of the short-wheelbase buses were rebodied with low-height double-deck bodies, enabling them to provide service on the Victoria Peak.
However, the Fleetlines in Hong Kong were unreliable and poor in climbing slopes, so CMB and KMB had to find the alternatives.
CMB evaluated the Ashok Leyland Titan, Scania Metropolitan and Volvo Ailsa B55, but these models were not successful.
KMB evaluated the Guy Victory J modified by Bus Bodies (South Africa) Limited and Dennis Jubilant.
KMB and CMB purchased large number of Dennis Jubilant and Leyland Victory Mark 2 buses in late-1970s/early-1980s.
CMB introduced two suburban coach routes in 1978, using the first model of second generation rear-engined double-decker (MCW Metrobus) in Hong Kong.
In the early 1980s, CMB and KMB acquired a number of second-hand buses from UK, but this time all of them were ex-London Transport Daimler/Leyland Fleetlines.
In 1980, KMB started to evaluate air-conditioned double-deckers, but the trial was unsuccessful and the air-conditioners of the two buses (one Dennis Jubilant and one Leyland Victory Mark 2) were removed in 1983.
Following the end of restriction of buying new buses from countries of Commonwealth of Nations, KMB introduced one German-built Mercedes-Benz O305 double-decker in 1983.
In 1985, KMB upgraded its airport coach service by introducing air-conditioned Dennis Falcon, which had the air conditioner driven by the main engine.
In 2003, KMB introduced the first new generation super low floor double-decker (TransBus Enviro500) with wider (with the width of 2550mm instead of 2500mm) bodywork and straight staircase.
In June 2003, Citybus was acquired by Chow Tai Fook Enterprises, the parent company of its major rival operator New World First Bus.
In 2013, KMB evaluated one BYD K9A fully electric single-decker bus,[1] including a one-month trial run on route 2.
In 2014, KMB, New World First Bus and Citybus introduced its first series diesel-electric hybrid buses, which is funded by the Hong Kong Government for trial of at least two years.
[2] Also during the same year, KMB and Citybus launched their first 12.8-metre high-capacity buses, which it claims would be more environmentally friendly since its larger capacity means carrying more passengers with fewer vehicles on road.