Abstract: A system for controlling a direct current series motor for driving an electric vehicle wherein a brake switch and an interlocking means prevent energization of the motor under certain conditions. The brake switch functions as a dead man's control to render the system inoperative whenever the operator leaves the vehicle unattended. If a direction controlling switch was previously left in a forward or reverse position, the interlocking means requires that the direction controlling switch be returned to a neutral position and then set in the desired forward or reverse position before energization of the motor occurs. The interlocking means, by necessitating return of the direction controlling switch to the neutral position before permitting energization of the motor, prevents the vehicle from moving unexpectedly in an undesired direction or at an excessive or dangerous rate of acceleration.