Turn signal neglects have been identified as among the main contributors to motorcycle crashes and injuries in Malaysia. To date, several prior naturalistic observational studies have been conducted to address this situation. Nevertheless, aspects including the use of turn signals for various motorcycle movements, factors contributing to such use and how the motorcycle riders initiate and cancel the turn signals were still lacking. Thus, this study was initiated to address the aforementioned gaps through in-vehicle video recordings from the perspective of a car driver, along the pre-determined routes in several locations in Selangor and Kuala Lumpur, Malaysia. Based on the 3963 observations, the multivariate logistic regression analysis revealed that female riders and those who wore helmets, carried a pillion, ingressed and egressed the expressways, turned at the 3-legged unsignalized intersections, entered the roundabouts, performed right turns, and travelled on weekdays, at dawn, dusk, night, during inclement weather, and on single carriageway, and single lanes were significantly more likely to activate their turn signals. The results also indicated that the majority of riders initiated the turn signals before crossing the line either along expressways or at intersections. Longer duration of turn signal initiation and cancellation were observed at unsignalized intersections as compared to expressways and signalized intersections. These findings necessitate either the development of new or improvement of existing technological system to increase the use of turn signals among riders.
