Abstract: The purpose of this paper is to better quantify the effects at signal intersections with pre-rightturn lanes.Traffic flow data of several signalized intersections with pre-right-turn lanes in Kunming City,Jilin City and Changchun City of China were collected through videotaping,to analyze the interference between the vehicle flow and bicycle flow.It is found that with the increase of the bicycle traffic volume,the bicycle lanes become congested and bicycle traffic is more likely to encroach into the travel path of motor vehicles,and result in the excessive vehicle delays.On the basis of empirical data,a calculation model was developed to quantify the relationship between the oversaturated bicycle flow and the additional operating delay caused by the bicycles.The result of the analysis can be used to calculate the capacity of the signalized intersections with pre-right-turn lanes and assist in developing guidelines for installation of pre-right-turn lanes at signalized intersections.