In this study, we examined how young drivers respond to emergency braking while driving an experimental vehicle. To simulate a traffic signal, we installed an LED light in front of the vehicle which randomly turned from yellow to red. When the LED turned red, participants had to perform an abrupt brake and maintain it for 3 s. We varied the ground contact position by adjusting the left knee joint angle during the experiment. However, changing the left foot's position did not show any significant effects on reaction time, accelerator release time, muscle activity, or foot pressure. Thus, we suggest that altering the left foot's position without adjusting the seat may not affect young drivers’ ability to use the right foot pedal We recommend that future studies focus on older individuals and investigate the impact of the left foot grounding position during emergency braking, as well as during normal driving conditions.