This document describes a system to automatically lock a vehicle's engine if the driver is detected to be over the legal alcohol limit. The system uses an Arduino board connected to an MQ3 alcohol sensor, GSM module, LCD display, and DC motor. If the sensor detects alcohol levels above the limit when the engine is started, it will send a notification message via GSM, display a message on the LCD, and trigger the motor to lock, preventing the vehicle from being driven under the influence of alcohol. The goal is to increase road safety by preventing drunk driving accidents. It proposes hardware and software requirements and provides examples of potential future enhancements like GPS and health monitoring.