Motorcycle riders exceeding speed limits and driving on the opposite traffic lane in curves has been identified as an acute traffic safety issue on many scenic mountain roads in Slovenia. The Slovenian Road Agency initiated a programme to research the possibilities of preventing such behaviour on these roads by innovative approach. Different types of visual velocity reducing measures have been implemented on nine selected curves on two roads frequently used by motorcycle riders. The measures consist of different patterns of horizontal road markings and other visual clues in form of vertical signalisation. The study compares the behaviour of the motorcycle riders before and after the implementation of the measures on the same test locations, each time during a period of three days including a sample of several hundred single motorcycle rides. The measured variables are the velocity, the distance from the road edge and the lean angle of the riders. They are determined by means of image analysis from calibrated video recordings. The analysis of the results has been done for each location to determine the correlation between the implemented measure and the change in the parameter variable values. The paper presents the data acquisition, the research and analysis methodology, and the results. The discussion evaluates the efficiency of the implemented measures, the possibilities of their seamless integration into the traffic legislation, as well as the requirements and the plans for further research.