Trailer buses are usually pulled by a conventional truck from various truck manufacturers, while others have larger space cabs. Trailer bus bodies are built by various local builders.
Early trailer bus designs emerged as early as 1924, with a large amount seeing service in the post war years. Several trailer buses continued in service in more remote and rugged areas such as South Africa, possibly due to the terrain, and availability of specialist bus builders as opposed to truck dealers and basic body builders.
An early Trailer bus was designed in Amsterdam in the 1920s as bus designs got longer. As a solution to possible grounding hazards on humped bridges 3 prototypes were built in 1924, but proved to be problematic and later converted to rigid bodies in 1927.
In the immediate post-war years after World War II, trailer buses were turned to as a cheap way of providing bus transport to replace worn out conventional bus fleets. The trailers were basic and uncomfortable, but served a purpose.
Even a double deck trailer bus was built.
The American truck manufacturer White built a trailer bus in 1947, now located in Sydney Bus Museum along with its tractor unit, a 1943 White M3A1, New South Wales, Australia. 123 semi-trailer type buses built and operated in Australia between 1939 and 1984. The Sydney exhibit was the last trailer bus used in NSW, withdrawn in 1977.
Trailer buses were also used in Perth, Australia, in 1952, purchased by Western Australian Government Railways with the trailer bodies built by Scarbrough Bus Services.
A large order for 1175 buses from the Netherlands Railways for buses from Crossley included an order for 250 trailer buses to carry 52 seated and 28 standing passengers. The tractor units were delivered as short Crossley DD42's, and these were matched in Holland with DAF built trailer chassis fitted with bus bodies.
Trailer buses saw service until at least 1984 in South Africa, and are still in service in Cuba, where they were introduced under the nickname of “camellos” (“camels”, from the twin-humped shape of the trailers) during the so-called “special period” after the fall of the Soviet Union. As of 2008, the trailer buses are reportedly being gradually retired from service in Havana city, replaced by Chinese-made buses.