Thank you, your comment.
I fixed another promblem too.
Original Code:
// Apply steering to the front wheels
vehicle.setSteeringValue(this.steering, 0);
vehicle.setSteeringValue(this.steering, 1);
// Apply engine and braking force to the back wheels
vehicle.applyEngineForce(this.engineForce, 2);
vehicle.setBrake(this.brakingForce, 2);
vehicle.applyEngineForce(this.engineForce, 3);
vehicle.setBrake(this.brakingForce, 3);
Change Like this:
// Apply steering to the front wheels
vehicle.setSteeringValue(this.steering, 0);
vehicle.setBrake(this.brakingForce, 0);
// Apply engine and braking force to the back wheels
vehicle.applyEngineForce(this.engineForce, 1);
vehicle.setBrake(this.brakingForce, 1);