Gap Acceptance Behaviour of Risky Right-Turning Motorcyclists from Minor Roads at Conventional and Unconventional T-Junctions

Right turning from a minor road is the most critical movement at T-junction, and the risk of right-turning motorcyclists involved in an accident is extremely high because of their riding behaviour. This study was carried out at three types of T-junctions which are type-A (conventional T-junction), type-B (unconventional T-junction with short exit lane for right-turning minor road vehicles) and type-C (unconventional T-junction with short exit lane for through major road vehicles). Results indicated that type-A T-junction is the safest as it has a lower percentage of risky riding behaviour. However, motorcyclists at type-B T-junction behaved better as most of them only performed one risky behaviour (56%) or none (34%). Additionally, results showed that motorcyclists accepted a smaller gap of 1.639 s for forced entry than the usual gap of 7.262 s. For gap acceptance behaviour involving a motorcycle and car making a right turn together, the mean accepted gap for this behaviour was 9.318 s for type-A, 8.319 s for type-B and 8.758 s for type-C. In conclusion, the geometrical configuration of type-B T-junction provides the best performance as the motorcyclists are more well-behaved and record the smallest value of the mean accepted gap.