First bus was operated in 1907. Thereafter, the number of vehicles were increased to 60,000 in 1953. At that time the population was 8.1 million.
Between 1958 and 1978, the Ceylon Transport Board (CTB) was the nationalised enterprise which handled all public bus transport in Sri Lanka. At its peak, it was the largest omnibus company in the world - with about 7,000 buses and over 50,000 employees. With privatization in 1979, it underwent a period of decline. The present number of buses in the fleet is 4500.
First broken up into several regional boards, then into several companies, it was finally reconstituted as the Sri Lanka Transport Board in 2005.
Source: From Web.