Motorcyclists are particularly vulnerable to road accidents due to limited protection and restricted visibility, especially in blind spot zones. This study presents the development and evaluation of a prototype smart helmet designed to enhance rider safety through an integrated blind spot detection system. The helmet employs ultrasonic sensors strategically mounted to detect nearby vehicles in the rider's blind spots. Real-time alerts are communicated through embedded visual and audio indicators, allowing the rider to make timely and informed decisions. The system architecture includes a microcontroller-based processing unit, rechargeable power supply, and a compact user interface for minimal rider distraction. Initial prototype testing under controlled conditions demonstrated high detection accuracy and rapid alert response times. The integration of this technology into standard protective gear holds significant potential for reducing collision risks and improving situational awareness among motorcyclists.