Abstract: The safety physiology characteristics of bicyclists on reverse riding conditions were studied for the purpose of reducing the influences of reverse riding on traffic flow and health condition of bicyclists, and improving roadway safety. High-resolution video cameras were utilized to obtain the proportion of reverse riding vehicles at three arteries' cross sections in Xi'an. The fitness wristband and cellphone were utilized to measure the riding speed and heart rate of the bicyclists. The time-domain theory was applied to compare the HRV characteristics between common and reverse riding. Corresponding improvements on reverse riding, including appropriate traffic management and control measures and the optimization of traffic facilities, were also provided to lead healthy and safe riding. The results indicate that there are more electrical reverse riding bicycles, however the traditional bicycle has a larger proportion of reverse riding. Reverse riding will lead to lower riding speed, higher heart rate and lower HRV, which may cause the sympathetic nerve hypertonia and be harmful to bicyclists.

Key words: safety physiology, bicyclists, reverse riding, heart rate variability(HRV), riding speed