Smart autoalarm guardrail is designed for helpping people emergency contact and remind the other drivers when car accident happen in remote area. People will drive on some remote area, or late night. If car accident happens, might be no one know the accident is happen. This design is help the litigant automatically make a emergency call, and send the location through the GPS when the car is crash the guardrail. As well as, it can turn on/flash the light within the accident area to warn the other drivers.