Abstract: This study is conducted for the objectives: 1) determine the nature and number of bicyc riders' violation behavior in China, which was done by a field observation; and 2) investigate whether sending information of bicycle direction and speed can increase the safety during the interaction between bicycles and motor vehicles. Motor vehicle drivers perceived risk in the interaction and their reaction performance were analyzed. The results show that bicycle riders committe a lot of violations and often put themselves in dangerous situations. At rush hours, 40.6% and 55.7% of them run through a red light for two observation sites, respectively. At non-rush hours, the percentage is 60.9% and 44.6%, respectively. Riding in the wrong direction is another serious regulation violation. The simulation results indicate, with bicycle information during interaction, it can result lower perceived risk, earlier reaction, lower speed when approaching, and longer separating distance providing (p<0.05).

Key words: bicycle riders, traffic regulation violation, perceived risk, vehicle-bicycle interaction safety