This paper presents the design and implementation of an Alcohol Detection with Engine Locking system for vehicles using the MQ-3 alcohol sensor, HC-SR04 ultrasonic sensor, and Arduino UNO as the Master Control Unit (MCU). The system continuously monitors alcohol concentration in the vehicle cabin and automatically locks the engine if the alcohol concentration exceeds the predefined threshold level. The proposed system also incorporates a SIM900A GSM module to send alert messages regarding the vehicle\\\'s whereabouts to designated authorities. Additionally, the ultrasonic sensor measures the distance between vehicles and activates warning indicators when the safe following distance is compromised. Experimental results demonstrate that the system provides an efficient and reliable solution to control accidents caused by drunk driving.
Mahendra et al. (2026) studied this question.