Buses have been a core mode of transport in Sri Lanka though their share is gradually falling. For instance, buses accounted for 65% of passengers crossing the Colombo Municipal Council (CMC) boundary in 1985, 57% in 1995, 55% in 2004 and 47% in 2013. The Sri Lanka Transport Board (SLTB) and private bus companies operate along roughly 680 and 400 inter-provincial bus routes in the Western Province, according to bus route information from the National Transport Commission (NTC). It is evident that most of the buses are operated in the seven major corridors in Western Province end in Pettah area where three bus terminals are located. Most of the inbound and outbound traffic of CMC use these seven major corridors of Galle, Negombo, Low Level, High Level, Horana, Malabe and Kandy (fig 1). Due to the traffic flow, these corridors are highly congested, especially during the peak hour. Another major impact on these corridors is that the average velocity of vehicles reduces significantly due to congestion and the lack of capacity of the roads. Especially, Horana and Low Level corridors as of recently experience high traffic flow but still have only 2 lanes capacity. These two corridors were developed recently due to the distribution of the traffic flow of the High Level corridor.

Amalan, T.P., & Liyanage, T.U. (2016). Bus passenger demand analysis in seven major corridors of Western Province [Extended Abstract]. In T.L. Gunaruwan (Ed.), Proceedings of 1st International Conference on Research for Transport and Logistics Industry 2016 (pp. 41-44). Sri Lanka Society of Transport and Logistics. https://slstl.lk/r4tli-2016/