Previous research found that less than five percent of motorcycle riders chose their trajectories in left-hand curves far enough to the right. Floor markings have a reputation of being slippery. Although they are not, riders avoid riding over them. The intervention, which was evaluated within this research, makes use of this stereotype. A set of nine curves was selected in three different regions of Austria, based on an accident analysis. After sound investigation, two types of floor markings were selected, the so-called “psycho-brake” and specific oval markings, both in order to keep riders away from the centre line. By automatic image processing, trajectories and driving speeds were determined before and after the intervention within more than 14,000 single observations. Both types of floor markings achieved significant changes of the riders’ trajectories. Riding speed hardly changed. A complementary survey collected rider’s impressions and opinions. The results suggest application of floor markings on areas riders should not drive over as a cheap and effective measure to improve road safety.