Factors associated with motorcyclists' speed behaviour on Malaysian roads

- This study determines the risk factors contributing to motorcycle speeding.
- This study use mixed effect logistic regression to analyzed motorcycle speeding outcome.
- This study shows that riding with excessive speed occurs regardless of the type of motorcycle.

This research uses data from observations of 8277 motorcyclists at various types of roads of the road hierarchy in Malaysia in 2015, to investigate the effects of road characteristics, motorcyclists' riding behaviour, motorcyclists' and motorcycles' characteristics on the occurrence of riding with excessive speed. For data collection and analysis, new software, i.e. MECHROM, was developed. The speed analysis shows that motorcyclists go faster than other vehicles on dual carriageway primary roads with three-lanes and dual carriageway collector roads with four-lanes. In general, 42.2% of the observed motorcycles exceed the speed limit and 28.6% of them go beyond the 85th percentile of the traffic speed. In determining the factors associated with motorcyclists riding with excessive speed, a mixed effect logistic regression model was produced, with three levels statistically significant random effect parameters. The fixed parameters factors are: primary road, roads with no shoulder, motorcycles with engine capacity of more than 150cc, not overloaded motorcycle, bright motorcycle, male rider, wears helmet and shoes, riding in the middle of the lane or shoulder, lane splitting (i.e. passing through in between two vehicles) and weaving between vehicles. The random parameters show that the majority of variation in the outcomes (56.5%) occurs at level 1 (the rider), while 12.2% of variation occurs at level 2 (motorcycle), and 31.2% at level 3 (location). The variations indicate that the motorcyclist's characteristics and riding behaviour are of importance, while the variable “type of motorcycle” clearly indicates that riding with excessive speed occurs regardless of the type of motorcycle.