Abstract: In urban areas where space is preciously limited,bus lanes can be created only by the conversion of exist-ing general-use lanes.If buses depart at a low frequency,the bus lanes will be under-utilized and road space will be was-ted.At bottleneck sections,in particular,non-bus vehicles will suffer greater delays.The paper focuses on this issue by proposing bus/car shared lanes within the selected bottlenecks.A method to estimate the capacity of shared lanes is pro-posed while considering the impacts of cars.The intersection of Huanggang Road and Xincai Road in Shenzhen was simu-lated as a case study.The results indicate that the delays of cars decrease while the buses'level of service (LOS)remains unaffected when less than 20% cars drive into the shared lane.However,the LOSs for buses and cars both decrease when more than 20% of cars are in the shared lane The study also concludes that car traffic in the shared lane has a great impact on the bottleneck's capacity.The delays of cars increase exponentially as car volumes in the shared lane increases.