As a solution to the rapid urbanization problem, interest in and use of personal mobility devices such as bicycles and electric kickboards are increasing, and accidents are also rising every year. In this study, a smart vest to prevent traffic accidents and promote safe driving of personal mobility users was designed and implemented. Unlike the existing products on the market that indicate directions using buttons, the smart vest designed and implemented in this study indicates the moving direction by shaking a bracelet and displays the direction by LEDs on the vest. Therefore, this product was designed and implemented to be safer and differentiated from other existing products.