A commercial vehicle is the backbone of the logistics industry which drives a vibrant economy of a country. Nevertheless, commercial or heavy vehicle-related accident is drawing serious attention. In 2014 alone, a total of 57,430 road accidents involving lorry, bus, and taxi was recorded (Kementerian Pengangkutan Malaysia, 2014). The height, weight and width dimension of the commercial vehicles reduce the visibility of other drivers and thereby increase the risk of an accident. Furthermore, due to the evolution of technology, larger trucks are now equipped with higher horsepower where a lot of speeding-related accidents were reported.
This study is set to evaluate the speed profile for different types of commercial vehicles at different road hierarchy. The speed profiles are of very useful in assisting the authority in road and infrastructure design. For instance, appropriate traffic calming measures can be deployed based on the speed profiles on the specific roads.
A total of 7168 commercial vehicles were observed on the four types of roads. Nearly 50% of them were collected on primary roads. About one-third of the samples were light lorry with two axles while two axles heavy lorry constituted 16%. The results indicate that in general most of the heavy vehicles (4.39%–98.61%) travelled fast and did not comply with the speed limits posted on different types of road hierarchy. The lower the posted speed limit the higher the percentage of non- compliance rates which means that the compliance increase as the speed limit increase. Majority of the commercial vehicles (28%–57%) occupied the middle lanes and those smaller sizes of vehicles (as compared to other sizes of commercial vehicles) had more tendencies to travel on the fast lane.