Abstract: The embodiment of this invention is a retractable spike pin snow tire. The retractable spike pin units are radially embedded in the road contact surface of specially designed vehicle tires. The retractable spike pin unit utilizes SMA (Shape Memory Alloy) actuators to provide mechanical forces for the spike pin. When activated electronically as needed by the driver, or by tire traction sensors, the plurality of spike pins will protrude out from the metal housings. These protruded pins will cling onto the ice covered or snow pressed road surface and provide needed extra grips for tires on slippery road conditions. When not in need the pins will be retracted back into their metal housing electronically by the driver's input, or by sensors.