Abstract
The purpose of this study is to research the difference in right-turning vehicledriver's cognition, judgment and gap acceptance characteristics on the type of oncoming vehicle. Right-turning vehicle drivers tended to ignore oncoming motorbikes or motorcycles more often than four-wheeled vehicles.
Right-turning vehicle used shorter gap for oncoming motorbike or motorcycle than for oncoming four-wheeled vehicle. In addition, the study reveals that judgment of right-turning depended on distance from right-turning vehicle to oncoming vehicle more stronger than on speed of oncoming vehicle. And it was found that oncoming motorbikes or motorcycles were recognized by right-turning vehicle drivers at a significantlylower rate.