Driving a vehicle in traffic conditions is highly risky. If the driver is not aware of the presence of a vehicle or obstacle in his blind spot, an accident can occur. The agenda of this proposed work is to suggest a solution to improve a driver's safety while changing lane, which focuses on the low-end vehicle. A blind spot detection system for protection against misshapen like vehicle collisions that causes loss of human lives. The system uses two different sensing positions in right and left side of the car. Ultrasonic sensors, Raspberry pi and a alarm are used to implement the design. The blind spot detection system will be useful while changing the lane, and with the help of this system the driver will come to know about presence of vehicle in blind spot which gives warning through alarm to driver.