This paper deduced the mathematical model for road capacity under the conservative and moderate behavior patterns, analyzed the relationship between the vehicular gap and the dynamic performance of the vehicle as well as the impacts of the improvement of vehicle performance on the vehicular gap. Meanwhile, based on the mathematical model established, it analyzed the impacts of the dynamic performance and the operation stability of the vehicles on the traffic capacity: the widespread application of advanced technology such as reliable mechanism design, ABS and automatic gear shifting, is advantageous to reduce the vehicular gap and improve the traffic capacity; the departure flow rate at the intersection will increase with the improvement of the accelerating ability of the vehicles; the realization of formation driving technology in the coming future will further upgrade the traffic capacity by leaps and bounds